Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
The rate dynamics in chemical or physical systems.
A species of gram-negative, anaerobic, spiral-shaped bacteria originally isolated from a saltwater pond in France. It contains a well-characterized metabolic pathway that enables it to survive transient contacts with OXYGEN.
Diazo derivatives of aniline, used as a reagent for sugars, ketones, and aldehydes. (Dorland, 28th ed)
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.
An enzyme that catalyzes the conversion of GTP to 3',5'-cyclic GMP and pyrophosphate. It also acts on ITP and dGTP. (From Enzyme Nomenclature, 1992) EC 4.6.1.2.
A highly poisonous compound that is an inhibitor of many metabolic processes, but has been shown to be an especially potent inhibitor of heme enzymes and hemeproteins. It is used in many industrial processes.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The inactive proenzyme of trypsin secreted by the pancreas, activated in the duodenum via cleavage by enteropeptidase. (Stedman, 25th ed)
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.
An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and CALMODULIN. The 20-kDa light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. The enzyme plays a central role in the regulation of smooth muscle contraction.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
The process of cleaving a chemical compound by the addition of a molecule of water.
Physiologically inactive substances that can be converted to active enzymes.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of GLYCEROPHOSPHOLIPIDS. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of PHOSPHATIDYLCHOLINE (EC 3.1.4.3), it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of PHOSPHATIDYLINOSITOLS.
Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Proteins prepared by recombinant DNA technology.
Diglycerides are a type of glyceride, specifically a form of lipid, that contains two fatty acid chains linked to a glycerol molecule by ester bonds.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Established cell cultures that have the potential to propagate indefinitely.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.
An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Contractile tissue that produces movement in animals.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
The sum of the weight of all the atoms in a molecule.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Elements of limited time intervals, contributing to particular results or situations.

A kinetic study of ribulose bisphosphate carboxylase from the photosynthetic bacterium Rhodospirillum rubrum. (1/44858)

The activation kinetics of purified Rhodospirillum rubrum ribulose bisphosphate carboxylase were analysed. The equilibrium constant for activation by CO(2) was 600 micron and that for activation by Mg2+ was 90 micron, and the second-order activation constant for the reaction of CO(2) with inactive enzyme (k+1) was 0.25 X 10(-3)min-1 . micron-1. The latter value was considerably lower than the k+1 for higher-plant enzyme (7 X 10(-3)-10 X 10(-3)min-1 . micron-1). 6-Phosphogluconate had little effect on the active enzyme, and increased the extent of activation of inactive enzyme. Ribulose bisphosphate also increased the extent of activation and did not inhibit the rate of activation. This effect might have been mediated through a reaction product, 2-phosphoglycolic acid, which also stimulated the extent of activation of the enzyme. The active enzyme had a Km (CO2) of 300 micron-CO2, a Km (ribulose bisphosphate) of 11--18 micron-ribulose bisphosphate and a Vmax. of up to 3 mumol/min per mg of protein. These data are discussed in relation to the proposed model for activation and catalysis of ribulose bisphosphate carboxylase.  (+info)

Nitric oxide stimulates the stress-activated protein kinase p38 in rat renal mesangial cells. (2/44858)

Nitric oxide (NO) has gained increased attention as a diffusible universal messenger that plays a crucial role in the pathogenesis of inflammatory and autoimmune diseases. Recently, we reported that exogenous NO is able to activate the stress-activated protein kinase (SAPK) cascade in mesangial cells. Here, we demonstrate that exposure of glomerular mesangial cells to compounds releasing NO, including spermine-NO and (Z)-1- (N-methyl-N-[6-(N-methylammoniohexyl)amino]diazen)-1-ium-1,2-diolate (MAHMA-NO), results in an activation of the stress-activated p38-mitogen-activated protein kinase (p38-MAPK) cascade as measured by the phosphorylation of the activator of transcription factor-2 (ATF2) in an immunocomplex kinase assay. Activation of the p38-MAPK cascade by a short stimulation (10 min) with the NO donor MAHMA-NO causes a large increase in ATF2 phosphorylation that is several times greater than that observed after stimulation with interleukin-1beta, a well-known activator of the p38-MAPK pathway. Time course studies reveal that MAHMA-NO causes rapid and maximal activation of p38-MAPK after 10 min of stimulation and that activation declines to basal levels within 60 min. The longer-lived NO donor spermine-NO causes a comparable rapid activation of the p38-MAPK pathway; however, the increased activation state of p38-MAPK was maintained for several hours before control values were reattained after 24 h of stimulation. Furthermore, the NO donors also activated the classical extracellular signal-regulated kinase (ERK) p44-MAPK cascade as shown by phosphorylation of the specific substrate cytosolic phospholipase A2 in an immunocomplex kinase reaction. Both MAHMA-NO and spermine-NO cause a rapid activation of p44-MAPK after 10 min of stimulation. Interestingly, there is a second delayed peak of p44-MAPK activation after 4-24 h of stimulation with NO donors. These results suggest that there is a differential activation pattern for stress-activated and mitogen-activated protein kinases by NO and that the integration of these signals may lead to specific cell responses.  (+info)

A Drosophila TNF-receptor-associated factor (TRAF) binds the ste20 kinase Misshapen and activates Jun kinase. (3/44858)

Two families of protein kinases that are closely related to Ste20 in their kinase domain have been identified - the p21-activated protein kinase (Pak) and SPS1 families [1-3]. In contrast to Pak family members, SPS1 family members do not bind and are not activated by GTP-bound p21Rac and Cdc42. We recently placed a member of the SPS1 family, called Misshapen (Msn), genetically upstream of the c-Jun amino-terminal (JNK) mitogen-activated protein (MAP) kinase module in Drosophila [4]. The failure to activate JNK in Drosophila leads to embryonic lethality due to the failure of these embryos to stimulate dorsal closure [5-8]. Msn probably functions as a MAP kinase kinase kinase kinase in Drosophila, activating the JNK pathway via an, as yet, undefined MAP kinase kinase kinase. We have identified a Drosophila TNF-receptor-associated factor, DTRAF1, by screening for Msn-interacting proteins using the yeast two-hybrid system. In contrast to the mammalian TRAFs that have been shown to activate JNK, DTRAF1 lacks an amino-terminal 'Ring-finger' domain, and overexpression of a truncated DTRAF1, consisting of only its TRAF domain, activates JNK. We also identified another DTRAF, DTRAF2, that contains an amino-terminal Ring-finger domain. Msn specifically binds the TRAF domain of DTRAF1 but not that of DTRAF2. In Drosophila, DTRAF1 is thus a good candidate for an upstream molecule that regulates the JNK pathway by interacting with, and activating, Msn. Consistent with this idea, expression of a dominant-negative Msn mutant protein blocks the activation of JNK by DTRAF1. Furthermore, coexpression of Msn with DTRAF1 leads to the synergistic activation of JNK. We have extended some of these observations to the mammalian homolog of Msn, Nck-interacting kinase (NIK), suggesting that TRAFs also play a critical role in regulating Ste20 kinases in mammals.  (+info)

Intracellular signalling: PDK1--a kinase at the hub of things. (4/44858)

Phosphoinositide-dependent kinase 1 (PDK1) is at the hub of many signalling pathways, activating PKB and PKC isoenzymes, as well as p70 S6 kinase and perhaps PKA. PDK1 action is determined by colocalization with substrate and by target site availability, features that may enable it to operate in both resting and stimulated cells.  (+info)

Bcl-2 regulates amplification of caspase activation by cytochrome c. (5/44858)

Caspases, a family of specific proteases, have central roles in apoptosis [1]. Caspase activation in response to diverse apoptotic stimuli involves the relocalisation of cytochrome c from mitochondria to the cytoplasm where it stimulates the proteolytic processing of caspase precursors. Cytochrome c release is controlled by members of the Bcl-2 family of apoptosis regulators [2] [3]. The anti-apoptotic members Bcl-2 and Bcl-xL may also control caspase activation independently of cytochrome c relocalisation or may inhibit a positive feedback mechanism [4] [5] [6] [7]. Here, we investigate the role of Bcl-2 family proteins in the regulation of caspase activation using a model cell-free system. We found that Bcl-2 and Bcl-xL set a threshold in the amount of cytochrome c required to activate caspases, even in soluble extracts lacking mitochondria. Addition of dATP (which stimulates the procaspase-processing factor Apaf-1 [8] [9]) overcame inhibition of caspase activation by Bcl-2, but did not prevent the control of cytochrome c release from mitochondria by Bcl-2. Cytochrome c release was accelerated by active caspase-3 and this positive feedback was negatively regulated by Bcl-2. These results provide evidence for a mechanism to amplify caspase activation that is suppressed at several distinct steps by Bcl-2, even after cytochrome c is released from mitochondria.  (+info)

Concomitant activation of pathways downstream of Grb2 and PI 3-kinase is required for MET-mediated metastasis. (6/44858)

The Met tyrosine kinase - the HGF receptor - induces cell transformation and metastasis when constitutively activated. Met signaling is mediated by phosphorylation of two carboxy-terminal tyrosines which act as docking sites for a number of SH2-containing molecules. These include Grb2 and p85 which couple the receptor, respectively, with Ras and PI 3-kinase. We previously showed that a Met mutant designed to obtain preferential coupling with Grb2 (Met2xGrb2) is permissive for motility, increases transformation, but - surprisingly - is impaired in causing invasion and metastasis. In this work we used Met mutants optimized for binding either p85 alone (Met2xPI3K) or p85 and Grb2 (MetPI3K/Grb2) to evaluate the relative importance of Ras and PI 3-kinase as downstream effectors of Met. Met2xPI3K was competent in eliciting motility, but not transformation, invasion, or metastasis. Conversely, MetP13K/Grb2 induced motility, transformation, invasion and metastasis as efficiently as wild type Met. Furthermore, the expression of constitutively active PI 3-kinase in cells transformed by the Met2xGrb2 mutant, fully rescued their ability to invade and metastasize. These data point to a central role for PI 3-kinase in Met-mediated invasiveness, and indicate that simultaneous activation of Ras and PI 3-kinase is required to unleash the Met metastatic potential.  (+info)

Activation of c-Abl tyrosine kinase requires caspase activation and is not involved in JNK/SAPK activation during apoptosis of human monocytic leukemia U937 cells. (7/44858)

Genotoxic stress triggers the activation of several sensor molecules, such as p53, JNK1/SAPK and c-Abl, and occasionally promotes the cells to apoptosis. We previously reported that JNK1/SAPK regulates genotoxic stress-induced apoptosis in p53-negative U937 cells by activating caspases. c-Abl is expected to act upstream of JNK1/SAPK activation upon treatment with genotoxic stressors, but its involvement in apoptosis development is still unclear. We herein investigated the kinase activities of c-Abl and JNK1/SAPK during apoptosis elicited by genotoxic anticancer drugs and tumor necrosis factor (TNF) in U937 cells and their apoptosis-resistant variant UK711 cells. We found that the activation of JNK1/SAPK and c-Abl correlated well with apoptosis development in these cell lines. Unexpectedly, however, the JNK1/SAPK activation preceded the c-Abl activation. Moreover, the caspase inhibitor Z-Asp suppressed c-Abl activation and the onset of apoptosis but not the JNK1/SAPK activation. Interestingly, c-Abl tyrosine kinase inhibition by CGP 57148 reduced apoptosis without interfering with JNK1/SAPK activation. These results indicate that c-Abl acts not upstream of JNK1/ SAPK but downstream of caspases during the development of p53-independent apoptosis and is possibly involved in accelerating execution of the cell death pathway.  (+info)

Activation of telomerase and its association with G1-phase of the cell cycle during UVB-induced skin tumorigenesis in SKH-1 hairless mouse. (8/44858)

Telomerase is a ribonucleoprotein enzyme that adds hexanucleotide repeats TTAGGG to the ends of chromosomes. Telomerase activation is known to play a crucial role in cell-immortalization and carcinogenesis. Telomerase is shown to have a correlation with cell cycle progression, which is controlled by the regulation of cyclins, cyclin dependent kinases (cdks) and cyclin dependent kinase inhibitors (cdkis). Abnormal expression of these regulatory molecules may cause alterations in cell cycle with uncontrolled cell growth, a universal feature of neoplasia. Skin cancer is the most prevalent form of cancer in humans and the solar UV radiation is its major cause. Here, we investigated modulation in telomerase activity and protein expression of cell cycle regulatory molecules during the development of UVB-induced tumors in SKH-1 hairless mice. The mice were exposed to 180 mjoules/cm2 UVB radiation, thrice weekly for 24 weeks. The animals were sacrificed at 4 week intervals and the studies were performed in epidermis. Telomerase activity was barely detectable in the epidermis of non-irradiated mouse. UVB exposure resulted in a progressive increase in telomerase activity starting from the 4th week of exposure. The increased telomerase activity either persisted or further increased with the increased exposure. In papillomas and carcinomas the enzyme activity was comparable and was 45-fold higher than in the epidermis of control mice. Western blot analysis showed an upregulation in the protein expression of cyclin D1 and cyclin E and their regulatory subunits cdk4 and cdk2 during the course of UVB exposure and in papillomas and carcinomas. The protein expression of cdk6 and ckis viz. p16/Ink4A, p21/Waf1 and p27/Kip1 did not show any significant change in UVB exposed skin, but significant upregulation was observed both in papillomas and carcinomas. The results suggest that telomerase activation may be involved in UVB-induced tumorigenesis in mouse skin and that increased telomerase activity may be associated with G1 phase of the cell cycle.  (+info)

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

'Desulfovibrio gigas' is a species of bacteria that belongs to the family Desulfovibrionaceae. These bacteria are gram-negative, curved rods and are commonly found in aquatic environments such as freshwater and marine sediments. They are capable of reducing sulfate to sulfide and are important organisms in the sulfur cycle in nature. 'Desulfovibrio gigas' is also known for its ability to grow under extreme conditions, such as high temperatures and pressures, making it a subject of interest in astrobiology and the search for extraterrestrial life.

It is worth noting that while this bacterium has been extensively studied in the field of microbiology, there may not be a specific medical definition associated with it, as it does not directly cause any known human diseases. However, understanding the physiology and metabolism of such extremophilic bacteria can provide insights into the limits of life and the potential for survival in extreme environments, both on Earth and beyond.

Phenylhydrazines are organic compounds that contain a phenyl group (a benzene ring with a hydrogen atom substituted by a hydroxy group) and a hydrazine group (-NH-NH2). They are aromatic amines that have been used in various chemical reactions, including the formation of azos and hydrazones. In medicine, phenylhydrazines were once used as vasodilators to treat angina pectoris, but their use has largely been discontinued due to their toxicity and potential carcinogenicity.

Calmodulin is a small, ubiquitous calcium-binding protein that plays a critical role in various intracellular signaling pathways. It functions as a calcium sensor, binding to and regulating the activity of numerous target proteins upon calcium ion (Ca^2+^) binding. Calmodulin is expressed in all eukaryotic cells and participates in many cellular processes, including muscle contraction, neurotransmitter release, gene expression, metabolism, and cell cycle progression.

The protein contains four EF-hand motifs that can bind Ca^2+^ ions. Upon calcium binding, conformational changes occur in the calmodulin structure, exposing hydrophobic surfaces that facilitate its interaction with target proteins. Calmodulin's targets include enzymes (such as protein kinases and phosphatases), ion channels, transporters, and cytoskeletal components. By modulating the activity of these proteins, calmodulin helps regulate essential cellular functions in response to changes in intracellular Ca^2+^ concentrations.

Calmodulin's molecular weight is approximately 17 kDa, and it consists of a single polypeptide chain with 148-150 amino acid residues. The protein can be found in both the cytoplasm and the nucleus of cells. In addition to its role as a calcium sensor, calmodulin has been implicated in various pathological conditions, including cancer, neurodegenerative diseases, and cardiovascular disorders.

Guanylate cyclase is an enzyme that catalyzes the conversion of guanosine triphosphate (GTP) to cyclic guanosine monophosphate (cGMP), which acts as a second messenger in various cellular signaling pathways. There are two main types of guanylate cyclases: soluble and membrane-bound. Soluble guanylate cyclase is activated by nitric oxide, while membrane-bound guanylate cyclase can be activated by natriuretic peptides. The increased levels of cGMP produced by guanylate cyclase can lead to a variety of cellular responses, including smooth muscle relaxation, neurotransmitter release, and regulation of ion channels. Dysregulation of guanylate cyclase activity has been implicated in several diseases, such as hypertension, heart failure, and cancer.

Potassium Cyanide (C6H5KN) is defined as a white, water-soluble, crystalline salt that is highly toxic. It is used in fumigation, electroplating, and metal cleaning. When combined with acids, it releases the deadly gas hydrogen cyanide. It can cause immediate death by inhibiting cellular respiration. It is also known as Cyanide of Potassium or Potassium Salt of Hydrocyanic Acid.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Trypsinogen is a precursor protein that is converted into the enzyme trypsin in the small intestine. It is produced by the pancreas and released into the duodenum, where it is activated by enterokinase, an enzyme produced by the intestinal mucosa. Trypsinogen plays a crucial role in digestion by helping to break down proteins into smaller peptides and individual amino acids.

In medical terms, an elevated level of trypsinogen in the blood may indicate pancreatic disease or injury, such as pancreatitis or pancreatic cancer. Therefore, measuring trypsinogen levels in the blood is sometimes used as a diagnostic tool to help identify these conditions.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Phosphorylation is the process of adding a phosphate group (a molecule consisting of one phosphorus atom and four oxygen atoms) to a protein or other organic molecule, which is usually done by enzymes called kinases. This post-translational modification can change the function, localization, or activity of the target molecule, playing a crucial role in various cellular processes such as signal transduction, metabolism, and regulation of gene expression. Phosphorylation is reversible, and the removal of the phosphate group is facilitated by enzymes called phosphatases.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Adenylate cyclase is an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). It plays a crucial role in various cellular processes, including signal transduction and metabolism. Adenylate cyclase is activated by hormones and neurotransmitters that bind to G-protein-coupled receptors on the cell membrane, leading to the production of cAMP, which then acts as a second messenger to regulate various intracellular responses. There are several isoforms of adenylate cyclase, each with distinct regulatory properties and subcellular localization.

Myosin-Light-Chain Kinase (MLCK) is an enzyme that plays a crucial role in muscle contraction. It phosphorylates the regulatory light chains of myosin, a protein involved in muscle contraction, leading to the activation of myosin and the initiation of the contractile process. MLCK is activated by calcium ions and calmodulin, and its activity is essential for various cellular processes, including cytokinesis, cell motility, and maintenance of cell shape. In addition to its role in muscle contraction, MLCK has been implicated in several pathological conditions, such as hypertension, atherosclerosis, and cancer.

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst, which remains unchanged at the end of the reaction. A catalyst lowers the activation energy required for the reaction to occur, thereby allowing the reaction to proceed more quickly and efficiently. This can be particularly important in biological systems, where enzymes act as catalysts to speed up metabolic reactions that are essential for life.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

Calcium-transporting ATPases, also known as calcium pumps, are a type of enzyme that use the energy from ATP (adenosine triphosphate) hydrolysis to transport calcium ions across membranes against their concentration gradient. This process helps maintain low intracellular calcium concentrations and is essential for various cellular functions, including muscle contraction, neurotransmitter release, and gene expression.

There are two main types of calcium-transporting ATPases: the sarcoplasmic/endoplasmic reticulum Ca^2+^-ATPase (SERCA) and the plasma membrane Ca^2+^-ATPase (PMCA). SERCA is found in the sarcoplasmic reticulum of muscle cells and endoplasmic reticulum of other cell types, where it pumps calcium ions into these organelles to initiate muscle relaxation or signal transduction. PMCA, on the other hand, is located in the plasma membrane and extrudes calcium ions from the cell to maintain low cytosolic calcium concentrations.

Calcium-transporting ATPases play a crucial role in maintaining calcium homeostasis in cells and are important targets for drug development in various diseases, including heart failure, hypertension, and neurological disorders.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Hydrolysis is a chemical process, not a medical one. However, it is relevant to medicine and biology.

Hydrolysis is the breakdown of a chemical compound due to its reaction with water, often resulting in the formation of two or more simpler compounds. In the context of physiology and medicine, hydrolysis is a crucial process in various biological reactions, such as the digestion of food molecules like proteins, carbohydrates, and fats. Enzymes called hydrolases catalyze these hydrolysis reactions to speed up the breakdown process in the body.

Enzyme precursors are typically referred to as zymogens or proenzymes. These are inactive forms of enzymes that can be activated under specific conditions. When the need for the enzyme's function arises, the proenzyme is converted into its active form through a process called proteolysis, where it is cleaved by another enzyme. This mechanism helps control and regulate the activation of certain enzymes in the body, preventing unwanted or premature reactions. A well-known example of an enzyme precursor is trypsinogen, which is converted into its active form, trypsin, in the digestive system.

Adenosine Triphosphate (ATP) is a high-energy molecule that stores and transports energy within cells. It is the main source of energy for most cellular processes, including muscle contraction, nerve impulse transmission, and protein synthesis. ATP is composed of a base (adenine), a sugar (ribose), and three phosphate groups. The bonds between these phosphate groups contain a significant amount of energy, which can be released when the bond between the second and third phosphate group is broken, resulting in the formation of adenosine diphosphate (ADP) and inorganic phosphate. This process is known as hydrolysis and can be catalyzed by various enzymes to drive a wide range of cellular functions. ATP can also be regenerated from ADP through various metabolic pathways, such as oxidative phosphorylation or substrate-level phosphorylation, allowing for the continuous supply of energy to cells.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

Type C phospholipases, also known as group CIA phospholipases or patatin-like phospholipase domain containing proteins (PNPLAs), are a subclass of phospholipases that specifically hydrolyze the sn-2 ester bond of glycerophospholipids. They belong to the PNPLA family, which includes nine members (PNPLA1-9) with diverse functions in lipid metabolism and cell signaling.

Type C phospholipases contain a patatin domain, which is a conserved region of approximately 240 amino acids that exhibits lipase and acyltransferase activities. These enzymes are primarily involved in the regulation of triglyceride metabolism, membrane remodeling, and cell signaling pathways.

PNPLA1 (adiponutrin) is mainly expressed in the liver and adipose tissue, where it plays a role in lipid droplet homeostasis and triglyceride hydrolysis. PNPLA2 (ATGL or desnutrin) is a key regulator of triglyceride metabolism, responsible for the initial step of triacylglycerol hydrolysis in adipose tissue and other tissues.

PNPLA3 (calcium-independent phospholipase A2 epsilon or iPLA2ε) is involved in membrane remodeling, arachidonic acid release, and cell signaling pathways. Mutations in PNPLA3 have been associated with an increased risk of developing nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease, and hepatic steatosis.

PNPLA4 (lipase maturation factor 1 or LMF1) is involved in the intracellular processing and trafficking of lipases, such as pancreatic lipase and hepatic lipase. PNPLA5 ( Mozart1 or GSPML) has been implicated in membrane trafficking and cell signaling pathways.

PNPLA6 (neuropathy target esterase or NTE) is primarily expressed in the brain, where it plays a role in maintaining neuronal integrity by regulating lipid metabolism. Mutations in PNPLA6 have been associated with neuropathy and cognitive impairment.

PNPLA7 (adiponutrin or ADPN) has been implicated in lipid droplet formation, triacylglycerol hydrolysis, and cell signaling pathways. Mutations in PNPLA7 have been associated with an increased risk of developing NAFLD and hepatic steatosis.

PNPLA8 (diglyceride lipase or DGLα) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA9 (calcium-independent phospholipase A2 gamma or iPLA2γ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA10 (calcium-independent phospholipase A2 delta or iPLA2δ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA11 (calcium-independent phospholipase A2 epsilon or iPLA2ε) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA12 (calcium-independent phospholipase A2 zeta or iPLA2ζ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA13 (calcium-independent phospholipase A2 eta or iPLA2η) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA14 (calcium-independent phospholipase A2 theta or iPLA2θ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA15 (calcium-independent phospholipase A2 iota or iPLA2ι) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA16 (calcium-independent phospholipase A2 kappa or iPLA2κ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA17 (calcium-independent phospholipase A2 lambda or iPLA2λ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA18 (calcium-independent phospholipase A2 mu or iPLA2μ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA19 (calcium-independent phospholipase A2 nu or iPLA2ν) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA20 (calcium-independent phospholipase A2 xi or iPLA2ξ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA21 (calcium-independent phospholipase A2 omicron or iPLA2ο) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA22 (calcium-independent phospholipase A2 pi or iPLA2π) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA23 (calcium-independent phospholipase A2 rho or iPLA2ρ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA24 (calcium-independent phospholipase A2 sigma or iPLA2σ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA25 (calcium-independent phospholipase A2 tau or iPLA2τ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA26 (calcium-independent phospholipase A2 upsilon or iPLA2υ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA27 (calcium-independent phospholipase A2 phi or iPLA2φ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA28 (calcium-independent phospholipase A2 chi or iPLA2χ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA29 (calcium-independent phospholipase A2 psi or iPLA2ψ) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA30 (calcium-independent phospholipase A2 omega or iPLA2ω) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA31 (calcium-independent phospholipase A2 pi or iPLA2π) has been implicated in membrane remodeling, arachidonic acid release, and cell signaling pathways.

PNPLA32 (calcium-independent phospholipase A2 rho or iPLA2ρ) is involved in the regulation of intracellular triacylglycerol metabolism, particularly in adipocytes and muscle cells. PNPLA33 (calcium-independent phospholipase A2 sigma or iPLA2σ) has been implicated in membrane remodeling, ar

Isoenzymes, also known as isoforms, are multiple forms of an enzyme that catalyze the same chemical reaction but differ in their amino acid sequence, structure, and/or kinetic properties. They are encoded by different genes or alternative splicing of the same gene. Isoenzymes can be found in various tissues and organs, and they play a crucial role in biological processes such as metabolism, detoxification, and cell signaling. Measurement of isoenzyme levels in body fluids (such as blood) can provide valuable diagnostic information for certain medical conditions, including tissue damage, inflammation, and various diseases.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

Diacylglycerols (also known as diglycerides) are a type of glyceride, which is a compound that consists of glycerol and one or more fatty acids. Diacylglycerols contain two fatty acid chains bonded to a glycerol molecule through ester linkages. They are important intermediates in the metabolism of lipids and can be found in many types of food, including vegetable oils and dairy products. In the body, diacylglycerols can serve as a source of energy and can also play roles in cell signaling processes.

Magnesium is an essential mineral that plays a crucial role in various biological processes in the human body. It is the fourth most abundant cation in the body and is involved in over 300 enzymatic reactions, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium also contributes to the structural development of bones and teeth.

In medical terms, magnesium deficiency can lead to several health issues, such as muscle cramps, weakness, heart arrhythmias, and seizures. On the other hand, excessive magnesium levels can cause symptoms like diarrhea, nausea, and muscle weakness. Magnesium supplements or magnesium-rich foods are often recommended to maintain optimal magnesium levels in the body.

Some common dietary sources of magnesium include leafy green vegetables, nuts, seeds, legumes, whole grains, and dairy products. Magnesium is also available in various forms as a dietary supplement, including magnesium oxide, magnesium citrate, magnesium chloride, and magnesium glycinate.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

Site-directed mutagenesis is a molecular biology technique used to introduce specific and targeted changes to a specific DNA sequence. This process involves creating a new variant of a gene or a specific region of interest within a DNA molecule by introducing a planned, deliberate change, or mutation, at a predetermined site within the DNA sequence.

The methodology typically involves the use of molecular tools such as PCR (polymerase chain reaction), restriction enzymes, and/or ligases to introduce the desired mutation(s) into a plasmid or other vector containing the target DNA sequence. The resulting modified DNA molecule can then be used to transform host cells, allowing for the production of large quantities of the mutated gene or protein for further study.

Site-directed mutagenesis is a valuable tool in basic research, drug discovery, and biotechnology applications where specific changes to a DNA sequence are required to understand gene function, investigate protein structure/function relationships, or engineer novel biological properties into existing genes or proteins.

A catalytic domain is a portion or region within a protein that contains the active site, where the chemical reactions necessary for the protein's function are carried out. This domain is responsible for the catalysis of biological reactions, hence the name "catalytic domain." The catalytic domain is often composed of specific amino acid residues that come together to form the active site, creating a unique three-dimensional structure that enables the protein to perform its specific function.

In enzymes, for example, the catalytic domain contains the residues that bind and convert substrates into products through chemical reactions. In receptors, the catalytic domain may be involved in signal transduction or other regulatory functions. Understanding the structure and function of catalytic domains is crucial to understanding the mechanisms of protein function and can provide valuable insights for drug design and therapeutic interventions.

Phospholipids are a major class of lipids that consist of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The head is composed of a phosphate group, which is often bound to an organic molecule such as choline, ethanolamine, serine or inositol. The tails are made up of two fatty acid chains.

Phospholipids are a key component of cell membranes and play a crucial role in maintaining the structural integrity and function of the cell. They form a lipid bilayer, with the hydrophilic heads facing outwards and the hydrophobic tails facing inwards, creating a barrier that separates the interior of the cell from the outside environment.

Phospholipids are also involved in various cellular processes such as signal transduction, intracellular trafficking, and protein function regulation. Additionally, they serve as emulsifiers in the digestive system, helping to break down fats in the diet.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

Nitric oxide (NO) is a molecule made up of one nitrogen atom and one oxygen atom. In the body, it is a crucial signaling molecule involved in various physiological processes such as vasodilation, immune response, neurotransmission, and inhibition of platelet aggregation. It is produced naturally by the enzyme nitric oxide synthase (NOS) from the amino acid L-arginine. Inhaled nitric oxide is used medically to treat pulmonary hypertension in newborns and adults, as it helps to relax and widen blood vessels, improving oxygenation and blood flow.

Protein kinases are a group of enzymes that play a crucial role in many cellular processes by adding phosphate groups to other proteins, a process known as phosphorylation. This modification can activate or deactivate the target protein's function, thereby regulating various signaling pathways within the cell. Protein kinases are essential for numerous biological functions, including metabolism, signal transduction, cell cycle progression, and apoptosis (programmed cell death). Abnormal regulation of protein kinases has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

Macromolecular substances, also known as macromolecules, are large, complex molecules made up of repeating subunits called monomers. These substances are formed through polymerization, a process in which many small molecules combine to form a larger one. Macromolecular substances can be naturally occurring, such as proteins, DNA, and carbohydrates, or synthetic, such as plastics and synthetic fibers.

In the context of medicine, macromolecular substances are often used in the development of drugs and medical devices. For example, some drugs are designed to bind to specific macromolecules in the body, such as proteins or DNA, in order to alter their function and produce a therapeutic effect. Additionally, macromolecular substances may be used in the creation of medical implants, such as artificial joints and heart valves, due to their strength and durability.

It is important for healthcare professionals to have an understanding of macromolecular substances and how they function in the body, as this knowledge can inform the development and use of medical treatments.

An amino acid substitution is a type of mutation in which one amino acid in a protein is replaced by another. This occurs when there is a change in the DNA sequence that codes for a particular amino acid in a protein. The genetic code is redundant, meaning that most amino acids are encoded by more than one codon (a sequence of three nucleotides). As a result, a single base pair change in the DNA sequence may not necessarily lead to an amino acid substitution. However, if a change does occur, it can have a variety of effects on the protein's structure and function, depending on the nature of the substituted amino acids. Some substitutions may be harmless, while others may alter the protein's activity or stability, leading to disease.

Protein Kinase C (PKC) is a family of serine-threonine kinases that play crucial roles in various cellular signaling pathways. These enzymes are activated by second messengers such as diacylglycerol (DAG) and calcium ions (Ca2+), which result from the activation of cell surface receptors like G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs).

Once activated, PKC proteins phosphorylate downstream target proteins, thereby modulating their activities. This regulation is involved in numerous cellular processes, including cell growth, differentiation, apoptosis, and membrane trafficking. There are at least 10 isoforms of PKC, classified into three subfamilies based on their second messenger requirements and structural features: conventional (cPKC; α, βI, βII, and γ), novel (nPKC; δ, ε, η, and θ), and atypical (aPKC; ζ and ι/λ). Dysregulation of PKC signaling has been implicated in several diseases, such as cancer, diabetes, and neurological disorders.

Nitric Oxide Synthase (NOS) is a group of enzymes that catalyze the production of nitric oxide (NO) from L-arginine. There are three distinct isoforms of NOS, each with different expression patterns and functions:

1. Neuronal Nitric Oxide Synthase (nNOS or NOS1): This isoform is primarily expressed in the nervous system and plays a role in neurotransmission, synaptic plasticity, and learning and memory processes.
2. Inducible Nitric Oxide Synthase (iNOS or NOS2): This isoform is induced by various stimuli such as cytokines, lipopolysaccharides, and hypoxia in a variety of cells including immune cells, endothelial cells, and smooth muscle cells. iNOS produces large amounts of NO, which functions as a potent effector molecule in the immune response, particularly in the defense against microbial pathogens.
3. Endothelial Nitric Oxide Synthase (eNOS or NOS3): This isoform is constitutively expressed in endothelial cells and produces low levels of NO that play a crucial role in maintaining vascular homeostasis by regulating vasodilation, inhibiting platelet aggregation, and preventing smooth muscle cell proliferation.

Overall, NOS plays an essential role in various physiological processes, including neurotransmission, immune response, cardiovascular function, and respiratory regulation. Dysregulation of NOS activity has been implicated in several pathological conditions such as hypertension, atherosclerosis, neurodegenerative diseases, and inflammatory disorders.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

X-ray crystallography is a technique used in structural biology to determine the three-dimensional arrangement of atoms in a crystal lattice. In this method, a beam of X-rays is directed at a crystal and diffracts, or spreads out, into a pattern of spots called reflections. The intensity and angle of each reflection are measured and used to create an electron density map, which reveals the position and type of atoms in the crystal. This information can be used to determine the molecular structure of a compound, including its shape, size, and chemical bonds. X-ray crystallography is a powerful tool for understanding the structure and function of biological macromolecules such as proteins and nucleic acids.

A muscle is a soft tissue in our body that contracts to produce force and motion. It is composed mainly of specialized cells called muscle fibers, which are bound together by connective tissue. There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac. Skeletal muscles attach to bones and help in movement, while smooth muscles are found within the walls of organs and blood vessels, helping with functions like digestion and circulation. Cardiac muscle is the specific type that makes up the heart, allowing it to pump blood throughout the body.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

Hydrogen-ion concentration, also known as pH, is a measure of the acidity or basicity of a solution. It is defined as the negative logarithm (to the base 10) of the hydrogen ion activity in a solution. The standard unit of measurement is the pH unit. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic.

In medical terms, hydrogen-ion concentration is important for maintaining homeostasis within the body. For example, in the stomach, a high hydrogen-ion concentration (low pH) is necessary for the digestion of food. However, in other parts of the body such as blood, a high hydrogen-ion concentration can be harmful and lead to acidosis. Conversely, a low hydrogen-ion concentration (high pH) in the blood can lead to alkalosis. Both acidosis and alkalosis can have serious consequences on various organ systems if not corrected.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

A peptide fragment is a short chain of amino acids that is derived from a larger peptide or protein through various biological or chemical processes. These fragments can result from the natural breakdown of proteins in the body during regular physiological processes, such as digestion, or they can be produced experimentally in a laboratory setting for research or therapeutic purposes.

Peptide fragments are often used in research to map the structure and function of larger peptides and proteins, as well as to study their interactions with other molecules. In some cases, peptide fragments may also have biological activity of their own and can be developed into drugs or diagnostic tools. For example, certain peptide fragments derived from hormones or neurotransmitters may bind to receptors in the body and mimic or block the effects of the full-length molecule.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Activation of the enzyme leading to H2O2 production. Agmatine sulfate injection can increase food intake with carbohydrate ... Both differential inhibition and activation of NO synthase (NOS) isoforms is reported. Polyamine metabolism. Agmatine is a ... Matrix metalloproteases (MMPs). Indirect down-regulation of the enzymes MMP 2 and 9. Advanced glycation end product (AGE) ... "Agmatine enhances the NADPH oxidase activity of neuronal NO synthase and leads to oxidative inactivation of the enzyme". ...
Involvement of serine 54 in the enzyme activation". The Journal of Biological Chemistry. 271 (28): 16526-34. doi:10.1074/jbc. ... cAMP-specific 3',5'-cyclic phosphodiesterase 4D is an enzyme that in humans is encoded by the PDE4D gene. The PDE4D gene is ... Sette C, Conti M (Jul 1996). "Phosphorylation and activation of a cAMP-specific phosphodiesterase by the cAMP-dependent protein ...
PI-3K is composed of a regulatory subunit (P85) and a catalytic subunit (P110). P85 regulates the activation of PI-3K enzyme. ... An example of positive feedback mechanism in the insulin transduction pathway is the activation of some enzymes that inhibit ... Other enzymes will push the pathway forward causing a positive feedback like the AKT and P70 enzymes. When insulin binds to its ... Different enzymes control this pathway. Some of these enzymes constrict the pathway causing a negative feedback like the GSK-3 ...
Together they published four papers on enzyme activation. In 1910, Dochez became an assistant resident and bacteriologist at ...
He contributed to the general field of enzyme kinetics by studying activation and inhibition. He made a sceptical study of the ... Ogston, A G (1955). "Activation and inhibition of enzymes". Discuss. Faraday Soc. 20 (20): 161-167. doi:10.1039/df9552000161. ... Thus a chiral enzyme such as aconitase can act differently on two apparently equivalent groups on a prochiral molecule, so ... Ogston pointed out that when a symmetrical molecule is placed in an asymmetric environment, such as the surface of an enzyme, ...
Decker H, Schweikardt T, Nillius D, Salzbrunn U, Jaenicke E, Tuczek F (August 2007). "Similar enzyme activation and catalysis ... as do the enzymes tyrosinase and catechol oxidase. In both cases inactive precursors to the enzymes (also called zymogens or ...
... which activates some of the cycle enzymes; and the RuBisCo enzyme activation, active in the Calvin cycle, which involves its ... The enzyme RuBisCo has its own, more complex activation process. It requires that a specific lysine amino acid be carbamylated ... The enzymes in the Calvin cycle are functionally equivalent to most enzymes used in other metabolic pathways such as ... The product of the first step is enediol-enzyme complex that can capture CO 2 or O 2. Thus, enediol-enzyme complex is the real ...
Evidence for C-terminal involvement in enzyme activation by lecithin". Arch. Biochem. Biophys. 327 (1): 45-52. doi:10.1006/abbi ... D-beta-hydroxybutyrate dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the BDH1 gene. This gene encodes ... The encoded protein forms a homotetrameric lipid-requiring enzyme of the mitochondrial membrane and has a specific requirement ... 2000). "Phosphatidylcholine activation of human heart (R)-3-hydroxybutyrate dehydrogenase mutants lacking active center ...
Rault M, Gontero B, Ricard J (May 1991). "Thioredoxin activation of phosphoribulokinase in a chloroplast multi-enzyme complex ... which may potentially transfer information between the two enzymes as well. Multi-enzyme complexes are likely to have more ... A catalytic residue in the enzyme (i.e. aspartate in RsPRK) deprotonates the O1 hydroxyl oxygen on RuP and activates it for ... More recent work on the regulation of eukaryotic PRK has focused on its ability to form multi-enzyme complexes with other ...
"Proteasome recruitment and activation of the Uch37 deubiquitinating enzyme by Adrm1". Nature Cell Biology. 8 (9): 994-1002. doi ... preventing random protein-enzyme encounter and uncontrolled protein degradation. The 19S regulatory particles can recognize ... "hRpn13/ADRM1/GP110 is a novel proteasome subunit that binds the deubiquitinating enzyme, UCH37". The EMBO Journal. 25 (24): ... "hRpn13/ADRM1/GP110 is a novel proteasome subunit that binds the deubiquitinating enzyme, UCH37". The EMBO Journal. 25 (24): ...
Jin J, Li X, Gygi SP, Harper JW (2007). "Dual E1 activation systems for ubiquitin differentially regulate E2 enzyme charging". ... Ubiquitin-like modifier-activating enzyme 6 is a protein that in humans is encoded by the UBA6 gene. GRCh38: Ensembl release 89 ... "Entrez Gene: UBE1L2 ubiquitin-activating enzyme E1-like 2". Hartley JL, Temple GF, Brasch MA (2001). "DNA Cloning Using In ... a novel E1 enzyme specific for ubiquitin". J Biol Chem. 282 (32): 23010-4. doi:10.1074/jbc.C700111200. PMID 17580310. " ...
Jin J, Li X, Gygi SP, Harper JW (June 2007). "Dual E1 activation systems for ubiquitin differentially regulate E2 enzyme ... Ubiquitin conjugating enzyme E2 Z (UBE2Z), also known as UBA6-specific E2 enzyme 1 (USE1), is an enzyme that in humans is ... This protein belongs to the ubiquitin conjugating enzyme family and is one of the E2 enzymes. UBE2Z spans 246 amino acids, 150 ... that is located at the enzyme's N-terminal and responsible for the enzyme's catalytic function. This UBC domain has a ...
Fibroblast activation protein alpha (FAP-alpha) also known as prolyl endopeptidase FAP is an enzyme that in humans is encoded ... "Antiplasmin-cleaving enzyme is a soluble form of fibroblast activation protein". Blood. 107 (4): 1397-404. doi:10.1182/blood- ... Bae S, Park CW, Son HK, Ju HK, Paik D, Jeon CJ, Koh GY, Kim J, Kim H (September 2008). "Fibroblast activation protein alpha ... "Entrez Gene: fibroblast activation protein, alpha". Garin-Chesa P, Old LJ, Rettig WJ (September 1990). "Cell surface ...
2002). "The FX enzyme is a functional component of lymphocyte activation". Cell. Immunol. 213 (2): 141-148. doi:10.1006/cimm. ... GDP-mannose 4,6 dehydratase is an enzyme that in humans is encoded by the GMDS gene. GRCh38: Ensembl release 89: ... 1998). "Molecular cloning and expression of GDP-D-mannose-4,6-dehydratase, a key enzyme for fucose metabolism defective in ... short-chain dehydrogenase/reductase and related enzymes) nomenclature initiative". Chem Biol Interact. 178 (1-3): 94-98. doi: ...
Activation of the Neurospora crassa enzyme by ammonium and rubidium ions". The Biochemical Journal. 209 (2): 527-31. doi: ... As such it was one of the earliest enzymes to show what was later described as allosteric behavior. The activation of mammalian ... The enzyme is expressed constitutively by most strains of C.diff, and can thus be easily detected in stool. Diagnosis is ... In plants, the enzyme can work in either direction depending on environment and stress. Transgenic plants expressing microbial ...
Leidecker O, Matic I, Mahata B, Pion E, Xirodimas DP (March 2012). "The ubiquitin E1 enzyme Ube1 mediates NEDD8 activation ... Jin J, Li X, Gygi SP, Harper JW (June 2007). "Dual E1 activation systems for ubiquitin differentially regulate E2 enzyme ... Ubiquitin-like modifier activating enzyme 1 (UBA1) is an enzyme which in humans is encoded by the UBA1 gene. UBA1 participates ... "Structural insights into E1-catalyzed ubiquitin activation and transfer to conjugating enzymes". Cell. 134 (2): 268-78. doi: ...
Schulman BA, Harper JW (May 2009). "Ubiquitin-like protein activation by E1 enzymes: the apex for downstream signalling ... Ubiquitin-activating enzyme (E1) starts the ubiquitination process (Figure 1). The E1 enzyme, along with ATP, binds to the ... Ubiquitin-activating enzymes, also known as E1 enzymes, catalyze the first step in the ubiquitination reaction, which (among ... "Structural insights into E1-catalyzed ubiquitin activation and transfer to conjugating enzymes". Cell. 134 (2): 268-78. doi: ...
The encoded enzyme is a negative regulator of thiopurine activation and toxicity. Mutations in this gene result in poor ... This gene encodes an enzyme that belongs to the Nudix hydrolase superfamily. Members of this superfamily catalyze the ...
2006). "Proteasome recruitment and activation of the Uch37 deubiquitinating enzyme by Adrm1". Nat. Cell Biol. 8 (9): 994-1002. ... Wicks SJ, Haros K, Maillard M, Song L, Cohen RE, Dijke PT, Chantry A (Dec 2005). "The deubiquitinating enzyme UCH37 interacts ... Ubiquitin carboxyl-terminal hydrolase isozyme L5 is an enzyme that in humans is encoded by the UCHL5 gene. GRCh38: Ensembl ... 2007). "hRpn13/ADRM1/GP110 is a novel proteasome subunit that binds the deubiquitinating enzyme, UCH37". EMBO J. 25 (24): 5742- ...
"Ribonucleotide activation by enzyme ribonucleotide reductase: understanding the role of the enzyme". Journal of Computational ... Class I RNR enzymes are constructed from large alpha subunit and small beta subunits which associate to form an active ... Organisms are not limited to having one class of enzymes. For example, E. coli have both class I and class III RNR. The ... A somewhat unusual feature of the RNR enzyme is that it catalyzes a reaction that proceeds via a free radical mechanism of ...
Ser-14 is modified by phosphorylase kinase during activation of the enzyme. Lys-680 is involved in binding the pyridoxal ... The enzyme phosphorylase kinase plays a role in phosphorylating glycogen phosphorylase to activate it and another enzyme, ... The associated enzyme deficiency was discovered in 1959 by W. F. H. M. Mommaerts et al. Dynamic symptoms of exercise ... The enzyme removes 1,4 glycosyl residues from outer branches of glycogen and adds inorganic phosphate to form glucose-1- ...
Enzyme activation is triggered by acidic pH and appears to be autocatalytic. Protein expression occurs after monocytes ... This enzyme may be involved in the processing of bacterial peptides and endogenous proteins for MHC class II presentation in ... 1998). "Autocatalytic activation of human legumain at aspartic acid residues". FEBS Lett. 438 (1-2): 114-8. doi:10.1016/S0014- ... Chen JM, Fortunato M, Barrett AJ (2001). "Activation of human prolegumain by cleavage at a C-terminal asparagine residue". ...
These are produced by intrapancreatic activation of pancreatic enzymes. Lipase activation produces the necrosis of fat tissue ... The activation of these digestive enzymes lead to inflammation, edema, vascular injury, and even cellular death. The death of ... This occurs through inappropriate activation of inactive enzyme precursors called zymogens (or proenzymes) inside the pancreas ... 16 mmol/L E - Enzymes: LDH >600iu/L; AST >200iu/L A - Albumin 10 mmol/L Predicts mortality risk in pancreatitis with fewer ...
Fu PP, Xia Q, Lin G, Chou MW (2004). "Pyrrolizidine alkaloids--genotoxicity, metabolism enzymes, metabolic activation, and ... These tests and similarities in the peptide sequences of the proteins encoded by these genes to known enzymes indicate that one ... Further steps in loline biosynthesis are thought to proceed with sequential PLP-enzyme-catalyzed and oxidative decarboxylations ... coupled in a condensation reaction linking the γ-carbon in homoserine to the secondary amine in proline in a PLP-type enzyme- ...
Direct activation of enzymes by binding calcium is common; some other enzymes are activated by noncovalent association with ... Trypsin, a digestive enzyme, uses the first method; osteocalcin, a bone matrix protein, uses the third. Some other bone matrix ... as cofactors in many enzymes; and in fertilization. Calcium ions outside cells are important for maintaining the potential ... continuously reformed through neutron activation of natural 40Ca. Many other calcium radioisotopes are known, ranging from 35Ca ...
Because plants don't have decarboxylase enzyme for L-ornithine, it must be first converted into L-arginine. Arginine can then ... Metabolic Activation, and Mechanisms". Drug Metabolism Reviews. 36 (1): 1-55. doi:10.1081/DMR-120028426. PMID 15072438. S2CID ... These adducts can damage DNA, leading to genotoxicity and carcinogenesis, and liver enzymes and hepatocytes, leading to ... Fu, Peter P.; Xia, Qingsu; Lin, Ge; Chou, Ming W. (2004). "Pyrrolizidine Alkaloids-Genotoxicity, Metabolism Enzymes, ...
Removal of this region by proteolytic cleavage results in activation of the enzyme. This domain is also found, in one or more ... The pro-segment docks into the enzyme, shielding the substrate binding site, thereby promoting inhibition of the enzyme. ... The propeptide is removed by proteolytic cleavage; removal activating the enzyme. This family includes both microviridins and ... Proteinase propeptide inhibitors (sometimes referred to as activation peptides) are responsible for the modulation of folding ...
Yamamoto-Hino M, Goto S (May 2016). "Spätzle-Processing Enzyme-independent Activation of the Toll Pathway in Drosophila Innate ... Activation of these neurons induces the female to cease movement and orient herself towards the male to allow for mounting. If ... The enzymes needed for pigment synthesis are then transported to the cell's pigment granule, which holds pigment precursor ... It has been proposed that a second SPE-like enzyme similarly acts to activate spätzle, as loss of SPE does not completely ...
Many compounds require enzyme metabolic activation to become mutagenic and cause DNA damage. Furthermore, reactive ... Enzyme linked immunosorbent assay (ELISA): ELISA contains an antigen in solution that can bind with DNA adducts. Any remaining ... "Effects of monoterpenoids on in vivo DMBA-DNA adduct formation and on phase I hepatic metabolizing enzymes". Carcinogenesis. 12 ...
Que, Lawrence; Ho, Raymond Y. N. (1996). "Dioxygen Activation by Enzymes with Mononuclear Non-Heme Iron Active Sites". Chemical ... Wallar, Bradley J.; Lipscomb, John D. (1996). "Dioxygen Activation by Enzymes Containing Binuclear Non-Heme Iron Clusters". ... In biochemistry, non-heme iron proteins describe families of enzymes that utilize iron at the active site but lack heme ... Iron-sulfur proteins, including those that are enzymes, are not included in this definition. Some non-heme iron proteins ...
Explore activation energy, thermodynamic properties, and compare to chemical-catalysed reactions. Dive into the science of ... Discover the fascinating world of enzyme-catalysed transesterification reactions! ... The activation energy for a enzyme catalysed biodiesel production system were found to be 4.25 (kcal/mole) for monoglyceride ... Evaluation of Activation Energy and Thermodynamic Properties of Enzyme-Catalysed Transesterification Reactions () ...
366e) Activation of Enzymes in Organic Solvents by Immobilization on Silica Nanoparticles. Conference ...
In contrast, activation of IRF3 and ISRE signaling upon stimulation with TRIFΔRIP, cGAS/STING or RIG-I-CARD remained unaltered ... In this work, we have revealed that early viral protein UBCv1, the only known conjugating enzyme encoded by a virus, modulates ... Transient overexpression of UBCv1 impaired activation of NF-κB and AP-1 transcription factors induced by several agonists of ... a mutant disabled for ubiquitylation activity retained similar immunomodulatory activity as the wild-type enzyme, suggesting ...
Additional Possibility of Data Analysis of Enzyme Inhibition and Activation 2. Geometrical Portraits of Enzymatic Reactions for ... Equations for calculation of the ka and ki constants of enzyme activation and nontrivial types of enzyme inhibition. J. Biol. ... Additional Possibility of Data Analysis of Enzyme Inhibition and Activation 2. Geometrical Portraits of Enzymatic Reactions for ... Additional Possibility of Data Analysis of Enzyme Inhibition and Activation 2. Geometrical Portraits of Enzymatic Reactions for ...
... DSpace/Manakin ... A novel mechanism of PLA2 activation by co-fibril formation and associated conformational changes is suggested show less ...
S9 Activation Enzymes SOS ChromoTest kit Rat Liver extract ... S9 Activation Enzymes - SOS. S9 and Activation of Pro-Mutagens ... The Muta-ChromoPlate kit is recommended to be tested with and without the S9 Activation Enzymes. EBPIs S9 Activation Enzymes ... 5051S9 S9 Activation Enzymes (SOS-ChromoTest Kit).. S9 is a crude liver enzyme extract that can, under certain conditions, ... The 5051S9 Activation Enzymes contain enough liver enzymes and reagents for 12 sample plates (please contact EBPI info@ ...
The acetoacetate activation and cleavage enzyme system. scientific article published on 01 May 1953 ...
Enzyme inhibition and activation[edit]. Main article: Enzyme inhibitor. Kinetic scheme for reversible enzyme inhibitors.. ... cooperative and allosteric enzymes, interfacial and intracellular enzymes, processive enzymes and so forth. Some enzymes ... Enzyme kinetics is the study of the rates of enzyme-catalysed chemical reactions. In enzyme kinetics, the reaction rate is ... Enzyme assays are laboratory procedures that measure the rate of enzyme reactions. Since enzymes are not consumed by the ...
The biochemical function, modelled 3D-structure, gene cluster and evolutionary relationships of each of these enzymes were stu ... Characterization and diversity of the complete set of GH family 3 enzymes from Rhodothermus marinus DSM 4253 Sci Rep. 2020 Jan ... Enzyme Activation * Gene Order * Genes, Bacterial * Genetic Loci * Glycoside Hydrolases / chemistry * Glycoside Hydrolases / ... The six enzymes were clustered into three major evolutionary lineages of GH3: β-N-acetyl-glucosaminidases, β-1,4-glucosidases/β ...
Enzymes of Vitamin D Activation. Vitamin D metabolism has been well described elsewhere (127, 133-136). Cutaneous vitamin D3 ... Prosser DE, Jones G. Enzymes involved in the activation and inactivation of vitamin D. Trends Biochem Sci (2004) 29:664-73. doi ... These hydroxylases are cytochrome P450 enzymes (133, 134). They are encoded in nuclear DNA, but the enzymes themselves localize ... activation as a function of ancestry and autoimmune disease susceptibility (126) also implicated CD4+ Th cell activation in ...
... are important enzymes in metabolic elimination of endo- and xenobiotics. It was recently shown that addition of fatty acid free ... Nevertheless, since only few human UGT enzymes were tested for this phenomenon, we have now performed detailed enzyme kinetic ... The results shed new light on the complexity of the BSA effects on the activity and enzyme kinetics of the human UGTs. ... Enzyme Activation / drug effects * Glucuronosyltransferase / metabolism* * Humans * Isoenzymes / metabolism * Kinetics * ...
Cells use compartmentalization of enzymes as a strategy to regulate metabolic pathways and increase their efficiency1. The α- ... Activation of L-lactate oxidase by the formation of enzyme assemblies through liquid-liquid phase separation *Tomoto Ura ... Activation of L-lactate oxidase by the formation of enzyme assemblies through liquid-liquid phase separation *Tomoto Ura ... Peña, K. L., Castel, S. E., de Araujo, C., Espie, G. S. & Kimber, M. S. Structural basis of the oxidative activation of the ...
1) Enzyme activation step: 95°C for 3 minutes. 2) 40 PCR cycles of :. Melt: 95°C for 3 seconds. Anneal/ extend: 60°C for 30 ...
He contributed to the general field of enzyme kinetics by studying activation and inhibition. He made a sceptical study of the ... Ogston, A G (1955). "Activation and inhibition of enzymes". Discuss. Faraday Soc. 20 (20): 161-167. doi:10.1039/df9552000161. ... Thus a chiral enzyme such as aconitase can act differently on two apparently equivalent groups on a prochiral molecule, so ... Ogston pointed out that when a symmetrical molecule is placed in an asymmetric environment, such as the surface of an enzyme, ...
... can increase the activity of P-450 enzymes, which can increase the 25-hydroxylation and also the catabolism of vitamin D. ...
Disruption of the nsp10-nsp14 interaction abrogated the nsp10-driven activation of the nsp14 exoribonuclease. We further showed ... that the nsp10 surface interacting with nsp14 overlaps with the surface involved in the nsp10-mediated activation of nsp16 2-O ... Coronavirus Nsp10, a critical co-factor for activation of multiple replicative enzymes. ... a critical co-factor for activation of multiple replicative enzymes. Journal of Biological Chemistry, 2014, 289 (37), pp.25783- ...
Enzymes: Activation Energy and Mechanisms - Enzyme Catalysis aus dem Kurs Enzymes and Enzyme Kinetics. Verfügbar für PC ✓, ... Enzymes: Activation Energy and Mechanisms - Enzyme Catalysis von Kevin Ahern, PhD (1) ... Dozent des Vortrages Enzymes: Activation Energy and Mechanisms - Enzyme Catalysis. Kevin Ahern, PhD. Dr. Kevin Ahern is a ... Der Vortrag „Enzymes: Activation Energy and Mechanisms - Enzyme Catalysis" von Kevin Ahern, PhD ist Bestandteil des Kurses „ ...
Pathogen-Derived Effectors Trigger Protective Immunity via Activation of the Rac2 Enzyme and the IMD or Rip Kinase Signaling ... Dive into the research topics of Pathogen-Derived Effectors Trigger Protective Immunity via Activation of the Rac2 Enzyme and ... Pathogen-Derived Effectors Trigger Protective Immunity via Activation of the Rac2 Enzyme and the IMD or Rip Kinase Signaling ... Pathogen-Derived Effectors Trigger Protective Immunity via Activation of the Rac2 Enzyme and the IMD or Rip Kinase Signaling ...
Enzyme activation. *Processing of hemoglobin for use of its iron content. *Synthesis of plasma proteins, such as albumin, and ...
Furthermore, RalA activation was found to be at a higher level of activation in HCC stem cells that express CD133. Transgenic ... Activation and involvement of Ral GTPases in colorectal cancer.. Cancer Res. 2011; 71(1):206-15 [PubMed] Free Access to Full ... RalGEFs are activators of the related RalA and RalB small GTPases and we found activation of both in CRC cell lines and patient ... Enzyme Activation. *Signal Transduction. *Molecular Sequence Data. *ral GTP-Binding Proteins. *Amino Acid Sequence ...
... the photosynthetic capacity by inducing a reduced redox status that maintains the activation states of Calvin cycle enzymes. ... The activation status of RuBisCO, and the protein content and activity of RuBisCO activase, but not the total content and ... Determination of the activity of enzymes involved in the AsA-GSH cycle. To determine the activities of enzymes involved in the ... XG participated in measurements of activities of Calvin cycle enzymes and antioxidant enzymes. YHZ participated in analysis of ...
Categories: Enzyme Activation Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, CopyrightRestricted 1 ...
Adenosine Diphosphate/metabolism, Adenosine Triphosphatases/antagonists & inhibitors/*metabolism, Enzyme Activation, Enzyme ... Enzyme Activation; Enzyme Inhibitors/pharmacology; Lyases/antagonists & inhibitors/chemistry/*metabolism; Phenanthrolines/ ... We conclude that ATP hydrolysis by BchI+D is required for an activation step in the magnesium chelatase reaction, whereas... ( ... We conclude that ATP hydrolysis by BchI+D is required for an activation step in the magnesium chelatase reaction, whereas ...
Shiga toxin 1 acting on DNA in vitro is a heat-stable enzyme not requiring proteolytic activation journal, April 2004 * ...
Creating Versatile Metallo-Enzyme Environments for Selective C-H Activation Chemistry: Lignocellulose Deconstruction and Beyond ... The work supported by enzC-Hem (Creating Versatile Metallo-Enzyme Environments for Selective C-H Activation Chemistry: ... The newly engineered enzyme "is one of the most complex designed enzymes applied to organic chemistry to date," the article ... To create the new enzyme, the research team led by Prof. Green subjected the primitive enzyme BH32 to a process called directed ...
High expression of PIK3CA and PIK3CB leads to continuous activation of the PI3K enzyme. The PI3K/AKT/mTOR pathway is a key ... Ras activation is a key mechanism regulating cell survival, proliferation, and differentiation, as well as gene transcription. ... 7h, i), suggesting that mutation of KIF3C may be related to the activation of the PI3K and KCNQ1 potassium channels. ... The increased expression of KIF3C regulated by mutant ZNF513 further promotes the activation of PI3K and potassium channels. In ...
The UBA1 gene provides instructions for making the ubiquitin-activating enzyme E1. Learn about this gene and related health ... Ubiquitin-like protein activation by E1 enzymes: the apex for downstream signalling pathways. Nat Rev Mol Cell Biol. 2009 May; ... The UBA1 gene provides instructions for making the ubiquitin-activating enzyme E1. This enzyme is necessary for the ubiquitin- ... These variants reduce the activity, function, or production of the enzyme. This shortage of functional enzyme allows damaged or ...
... but combined with a fast 5-minute enzyme activation time. In addition, CoralLoad Concentrate, containing two gel-tracking dyes ... PCR Enzymes & Kits. End-Point PCR. HotStarTaq Plus Master Mix Kit. HotStarTaq Plus Master Mix Kit. For fast and highly specific ... Hot-start enzyme from Supplier AII. Supplier R. Supplier I (antibody-mediated). Manual. Wax barrier. ... Recombinant enzyme: Yes Substrate analogs: dNTP, ddNTP, dUTP, biotin-11-dUTP, DIG-11-dUTP, fluorescent-dNTP/ddNTP Extension ...
  • In this study, the activation energy and thermodynamic properties of immobilized enzyme catalysed transesterification reactions were evaluated based on the enzyme substrate transition theory. (scirp.org)
  • Such cases exist: for example, a mutase such as phosphoglucomutase catalyses the transfer of a phospho group from one position to another, and isomerase is a more general term for an enzyme that catalyses any one-substrate one-product reaction, such as triosephosphate isomerase . (wikipedia.org)
  • An example of enzymes that bind a single substrate and release multiple products are proteases , which cleave one protein substrate into two polypeptide products. (wikipedia.org)
  • in such cases, it is helpful to determine the enzyme structure with and without bound substrate analogues that do not undergo the enzymatic reaction. (wikipedia.org)
  • Beyond this limit the enzyme is saturated with substrate and the reaction rate ceases to increase. (wikipedia.org)
  • The binding of substrate induces a change in enzyme structure. (lecturio.de)
  • The prothrombinase complex is the enzymatic complex responsible for timely thrombin formation at the place of vascular injury and is composed of the enzyme, factor Xa (fXa), the non-enzymatic cofactor factor Va (fVa), and the substrate prothrombin assembled on a lipid membrane in the presence of divalent metal ions. (csuohio.edu)
  • When more reactant, or substrate, is added to a fixed amount of enzyme, the rate of the reaction increases as the enzyme can make more product. (jove.com)
  • For an enzyme-catalysed reaction, there is usually a hyperbolic relationship between the rate of reaction and the concentration of substrate, as shown below: (A) At low concentration of substrate, there is a steep increase in the rate of reaction with increasing substrate concentration. (meltingpointathens.com)
  • Typically, an enzyme is combined with a substrate to reduce the activation energy of a chemical reaction. (meltingpointathens.com)
  • In most biological environments, the concentration of the enzyme is lower than the concentration of the substrate. (meltingpointathens.com)
  • This occurs because as temperature is added there is more energy allowing the substrate to collide with the enzyme. (meltingpointathens.com)
  • The enzyme and the substrate are in the same area. (meltingpointathens.com)
  • Some situations have more than one substrate molecule that the enzyme will change. (meltingpointathens.com)
  • The enzyme grabs on to the substrate at a special area called the active site. (meltingpointathens.com)
  • K. R. Jegannathan, E. S. Chan and P. J. Ravindra, "Design an Immobilized Lipase Enzyme for Biodiesel Production," Journal of Molecular Catalysis B: Enzymatic, Vol. 58, 2009, pp. 78-83. (scirp.org)
  • In enzyme catalysis, which of the following statements is NOT true? (lecturio.de)
  • SORS:Exploring mechanistic details in enzyme catalysis through mutiscale hybrid QM/MM simulations. (bsc.es)
  • Minerals play an essential part in the activation or catalysis of enzymes. (home-remedies-for-you.com)
  • Enzyme kinetics is the study of the rates of enzyme-catalysed chemical reactions . (wikipedia.org)
  • Enzyme kinetics is the study of how an enzyme changes the rate of a reaction. (jove.com)
  • He made many studies of enzymes such as peroxidase and creatine phosphotransferase. (wikipedia.org)
  • Peroxidase enzymes have recently been shown to catalyze the activation of a wide variety of xenobiotic compounds to reactive intermediates and these enzymes, particularly prostaglandin H synthase, have been suggested to play a role in the extrahepatic toxicity and carcinogenicity of several compounds. (cdc.gov)
  • Since antioxidants are good electron donors we investigated whether BHT might be metabolically activated to BHT-quinone methide by peroxidase enzymes. (cdc.gov)
  • This study reports on the metabolic activation of BHT by two peroxidase enzymes: horseradish peroxidase and prostaglandin H synthase. (cdc.gov)
  • Most cases of VEXAS syndrome are caused by genetic variants that change the protein building block (amino acid) methione at position 41 in the ubiquitin-activating enzyme E1 to another amino acid. (medlineplus.gov)
  • However these enzymes can be increased in non-pancreatic disease, and dogs with confirmed pancr eatitis may also have normal amylase and lipase activity. (ivis.org)
  • Additional Possibility of Data Analysis of Enzyme Inhibition and Activation 2. (scialert.net)
  • Additional possibility of data analysis of enzyme inhibition and activation.1: Equations for calculation of the k a and k i constants of enzyme activation and nontrivial types of enzyme inhibition. (scialert.net)
  • Their experiments revealed that in its shape-shifting, Abl was precisely balanced between its inhibition and activation states, Kalodimos said. (stjude.org)
  • Studying an enzyme's kinetics in this way can reveal the catalytic mechanism of this enzyme, its role in metabolism , how its activity is controlled, and how a drug or a modifier ( inhibitor or activator ) might affect the rate. (wikipedia.org)
  • Metabolism of 1ーnitropyrene oxides and effect of nitrogen dioxide on arene activation. (nii.ac.jp)
  • Mutations in genes concerned with production of enzymes for metabolism of tobacco products may lead to increased risk of carcinogenesis with respect to oral mucosa. (bvsalud.org)
  • S9 is a crude liver enzyme extract that can, under certain conditions, convert materials without any genotoxic activity to active genotoxic entities. (biotoxicity.com)
  • For example, the liver enzyme CYP1A1 transforms otherwise harmless chemicals in tobacco smoke into carcinogens that can cause liver cancer . (naturalnews.com)
  • Laetrile has been used for cancer treatment both as a single agent and in combination with a metabolic therapy program that consists of a specialized diet, high-dose vitamin supplements, and pancreatic enzymes . (cancer.gov)
  • Proteinuria occurs in some dogs with acute pancreatitis, possibly as a consequence of pancreatic enzyme-mediated glomerular damage, and is usually transient. (ivis.org)
  • These effects include increased enzyme content, destabilization of lysosomal and zymogen granules, sustained increase in calcium overload, and activation of pancreatic stellate cells. (msdmanuals.com)
  • 1975. [Effect of methyl parathion or zineb administration on the activity of some hepatic enzymes in rats]. (cdc.gov)
  • The initial step in the metabolic activation process is the introduction of a hydroxyl group at the side chain at C-25 by the hepatic enzyme, CYP 27 (a vitamin D-25-hydroxylase). (medscape.com)
  • Thus a chiral enzyme such as aconitase can act differently on two apparently equivalent groups on a prochiral molecule, so citrate can be an intermediate in the tricarboxylate cycle. (wikipedia.org)
  • The enzyme aconitase catalyzes both steps, since the intermediate is cis -aconitate. (encyclopedia.com)
  • A powerful engineering tool for tailoring enzymes towards desired transformations, directed evolution improves the functions of proteins through repeated rounds of mutation and selection. (europa.eu)
  • This enzyme is necessary for the ubiquitin-proteasome system, which targets damaged or unneeded proteins to be broken down (degraded) within cells. (medlineplus.gov)
  • When a chain of ubiquitin proteins is attached to a protein, the protein is recognized and destroyed by a complex of enzymes called a proteasome. (medlineplus.gov)
  • As a result, damaged or unneeded proteins build up inside cells instead of being broken down, which may contribute to abnormal activation of immune cells or cell damage and death. (medlineplus.gov)
  • This shortage of functional enzyme allows damaged or unneeded proteins to build up inside cells instead of being broken down, which may damage cells and contribute to cell death. (medlineplus.gov)
  • Interestingly, recent data suggest a function for ULK1 not only during autophagy activation but also during elongation and closure of the autophagosomal membrane via binding to ATG8 proteins [ 8 ]. (hindawi.com)
  • Species differences in metabolic activation and inactivation of 1ーnitropyrene in the liver. (nii.ac.jp)
  • This is because several of the contaminants in technical grade methoxychlor are directly estrogenic (Kupfer and Bulger 1987b), whereas pure methoxychlor is proestrogenic and requires metabolic activation before exhibiting estrogenic activity (Bulger et al. (cdc.gov)
  • When enzymes bind multiple substrates, such as dihydrofolate reductase (shown right), enzyme kinetics can also show the sequence in which these substrates bind and the sequence in which products are released. (wikipedia.org)
  • This rate-determining step may be a chemical reaction or a conformational change of the enzyme or substrates, such as those involved in the release of product(s) from the enzyme. (wikipedia.org)
  • Nevertheless, since only few human UGT enzymes were tested for this phenomenon, we have now performed detailed enzyme kinetic analysis on the BSA effects in six previously untested UGTs, using 2-4 suitable substrates for each enzyme. (nih.gov)
  • Various products of these genes are enzymes involved in the activation or degradation of carcinogens/pro-carcinogens. (bvsalud.org)
  • The reaction catalysed by an enzyme uses exactly the same reactants and produces exactly the same products as the uncatalysed reaction. (wikipedia.org)
  • Enzymes speed up reactions by lowering the activation energy of the reactants. (jove.com)
  • The speed at which the enzyme turns reactants into products is called the rate of reaction. (jove.com)
  • Ogston pointed out that when a symmetrical molecule is placed in an asymmetric environment, such as the surface of an enzyme, supposedly identically placed groups become distinguishable. (wikipedia.org)
  • The Abl enzyme controls this switching through a process called allosteric regulation in which a part of the molecule distant from the molecule's on-off switch or kinase domain somehow inhibits or activates Abl. (stjude.org)
  • This contributes to the folding of the enzyme molecule, its shape, and the shape of the active site. (meltingpointathens.com)
  • Your liver creates a family of enzymes known as cytochrome P450 (CYP) that changes molecules in specific ways to make them less toxic. (naturalnews.com)
  • This reaction is presumably catalyzed by a cytochrome P-450 related enzyme. (cdc.gov)
  • The enzyme's over activation spurs mutated cells to the uncontrolled growth of leukemia. (stjude.org)
  • In hypoxia-ischemia, CaM kinase is over-activated, but hypothermia has been shown to decrease this enzyme's activation. (news-medical.net)
  • The results shed new light on the complexity of the BSA effects on the activity and enzyme kinetics of the human UGTs. (nih.gov)
  • The activation status of RuBisCO, and the protein content and activity of RuBisCO activase, but not the total content and transcripts of RuBisCO were closely related to the endogenous BR levels in different genotypes. (biomedcentral.com)
  • We conclude that ATP hydrolysis by BchI+D is required for an activation step in the magnesium chelatase reaction, whereas ATPase activity of BchH and the phosphate exchange activity of BchI participate in subsequent reactions leading to the insertion of Mg2+ into protoporphyrin IX. (lu.se)
  • These variants reduce the activity, function, or production of the enzyme. (medlineplus.gov)
  • St. Jude Children's Research Hospital structural biologists have deciphered how the structure of the enzyme called Abl regulates its activity, enabling the enzyme to switch itself on and off. (stjude.org)
  • Sulphotransferaseーmediated activation of the carcinogen 5ーhydroxyーmethylchrtsene,Species and sex differences in tissue distribution of the enzyme activity and a possible participation of hydroxysteroid sulphotransforases. (nii.ac.jp)
  • At what pH is the rate of enzyme activity the highest? (meltingpointathens.com)
  • How does pH affect enzyme activity graph? (meltingpointathens.com)
  • Extremely high or low pH values generally result in complete loss of activity for most enzymes. (meltingpointathens.com)
  • How does temperature affect enzyme activity lab report? (meltingpointathens.com)
  • Enzyme pH levels also change the shape of the active site and affect the rate of enzyme activity. (meltingpointathens.com)
  • Why does enzyme activity decrease at low temperatures? (meltingpointathens.com)
  • As the temperature decreases, so does enzyme activity. (meltingpointathens.com)
  • Compounds that inhibit the enzyme activity or activation of MATRIX METALLOPROTEINASES. (bvsalud.org)
  • Based on the present work and published literatures, the activation energy of enzyme-catalysed transesterification reactions were found to be lower than the chemical-catalysed and non-catalyzed transesterification reactions. (scirp.org)
  • R. Pogaku, J. Raman and G. Ravikumar, "Evaluation of Activation Energy and Thermodynamic Properties of Enzyme-Catalysed Transesterification Reactions," Advances in Chemical Engineering and Science , Vol. 2 No. 1, 2012, pp. 150-154. (scirp.org)
  • Applicability of vector presentation of enzymatic reactions to the analysis of enzyme activation and inhibition. (scialert.net)
  • Catalysts lower the activation energy for reactions. (meltingpointathens.com)
  • Thus enzymes speed up reactions by lowering activation energy. (meltingpointathens.com)
  • The drug has proven effective in treating CML by plugging into the kinase domain of the over-activated Abl enzyme and shutting it down. (stjude.org)
  • The experimental models were given standard cooling therapy (therapeutic hypothermia) alone and in combination with a selective Src kinase inhibitor, PP2, that blocks a regulatory enzyme of apoptosis (cell death), which intensifies as a result of hypoxia-ischemia. (news-medical.net)
  • We theorized that a Src kinase inhibitor, in addition to hypothermia, would further attenuate the activation of CaM kinase IV and that the result might be less brain damage,' explains Panagiotis Kratimenos, M.D., Ph.D., the study's lead author, and a specialist in neonatology and neonatal neurocritical care at Children's National. (news-medical.net)
  • The authors conclude that hypothermia alone attenuated the over-activation of CaM kinase IV and improved neuropathology after hypoxia. (news-medical.net)
  • However, the combination of hypothermia with Src kinase inhibition following hypoxia further attenuated the increased activation of CaM kinase IV, compared with hypothermia alone in the newborn experimental model brain. (news-medical.net)
  • In oxygen deprivation of the brain, the pathways leading to cell death are over-activated, including the nuclear enzyme CaM kinase IV. (news-medical.net)
  • These are termed xenobiotic-metabolizing enzymes (XMEs) found especially in the liver but also in the mucosa of the upper aerodigestive tract, and several are polymorphic and strongly influence individual biological responses to carcinogens. (bvsalud.org)
  • Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. (jove.com)
  • In contrast, activation of IRF3 and ISRE signaling upon stimulation with TRIFΔRIP, cGAS/STING or RIG-I-CARD remained unaltered. (mdpi.com)
  • Interestingly, stimulation of CysLT1R located in the nuclei induced the activation of ERK1/2, an enzyme which have been shown to mediate LTD4 induced proliferation. (lu.se)
  • The work supported by enzC-Hem (Creating Versatile Metallo-Enzyme Environments for Selective C-H Activation Chemistry: Lignocellulose Deconstruction and Beyond) shows that combining computational design and directed evolution could lead to new biocatalysts for important chemical transformations not found in nature. (europa.eu)
  • If the enzyme that controls either of these steps is deficient because of a mutation, vitamin D function is less than normal. (medscape.com)
  • The biochemical function, modelled 3D-structure, gene cluster and evolutionary relationships of each of these enzymes were studied. (nih.gov)
  • The UBA1 gene provides instructions for making the ubiquitin-activating enzyme E1. (medlineplus.gov)
  • Each of these terminators inhibits the transcription of the output gene and can be flipped by a different recombinase enzyme, making the terminator inactive. (sciencedaily.com)
  • Therapeutic strategies include the blocking of transcription factors such as NF-κB that lead to inflammatory gene activation and the inhibition of signaling pathways that are stimulated in lung diseases. (ersjournals.com)
  • The enzyme in the ES complex has a different structure than the enzyme alone. (lecturio.de)
  • The newly engineered enzyme "is one of the most complex designed enzymes applied to organic chemistry to date," the article reports. (europa.eu)
  • fVa contributes to the activation of prothrombin mainly by stabilizing the enzymatic complex and altering the kinetic mechanism of fXa (increased k cat ). (csuohio.edu)
  • The fact that NMR spectroscopy captures the complex conformation changes of molecules enabled the researchers to discover new details about how Abl's structure affected its activation state. (stjude.org)
  • Thioredoxin activation of phosphoribulokinase in a bi-enzyme complex from Chlamydomonas reinhardtii chloroplasts. (bio.net)
  • Increasing evidence suggests that respiratory epithelial cells with dysfunctional CFTR have exaggerated activation of NF-κB/inhibitor of NF-κB complex associated with upregulated expression of chemokines 4 , 5 . (ersjournals.com)
  • How CFTR dysfunction in CF airway cells contributes to the activation and nuclear localisation of NF-κB is still unclear. (ersjournals.com)
  • In this work, we have revealed that early viral protein UBCv1, the only known conjugating enzyme encoded by a virus, modulates innate immune and inflammatory signaling. (mdpi.com)
  • Furthermore, activation of autophagy allows to extend cell survival when exposed to different types of stressors such as starvation or cytotoxic drugs. (hindawi.com)
  • In CF disease, a nonregulated inflammatory lung response occurs through exaggerated nuclear factor (NF)-κB activation and elevated pro-inflammatory cytokines production by airway epithelial cells. (ersjournals.com)
  • This increase in the thrombin burst occurs after direct rFVIIa activation of factors IX and X on the surface of activated platelets (even in the absence of factor VIII or IX). (medscape.com)
  • The intermediate product in this oxidative decarboxylation reaction is oxalosuccinate, whose formation is coupled with the production of NADH + H + . While still bound to the enzyme, oxalosuccinate loses CO2 to produce alpha-ketoglutarate. (encyclopedia.com)
  • If the pH level is lower than 7 or higher than 11, the enzyme becomes denaturated and loses its structure. (meltingpointathens.com)
  • After 14 rounds of evolution, the research team succeeded in engineering an enzyme called BH32.14 that is significantly faster and is also enantioselective . (europa.eu)
  • These coenzymes are subsequently oxidized in the electron transport chain, where a series of enzymes transfers the electrons of NADH and FADH2 to oxygen, which is the final electron acceptor of cellular respiration in all eukaryotes. (encyclopedia.com)
  • In eukaryotic cells, the enzymes that are reponsible for this breakdown are located in the mitochondria, while in procaryotes they are in the cytoplasm. (encyclopedia.com)
  • To determine whether FP reduces cytokine production in bronchial epithelial cells via NF-κB, the authors investigated the nonstimulated and the Pseudomonas aeruginosa lipopolysaccharide (LPS) stimulated production of NF-κB-dependent interleukin (IL)-6, IL-8 and RANTES (regulated on activation, T-cell expressed and secreted) along with the activation of NF-κB in non-CF and CF human bronchial gland epithelial cells. (ersjournals.com)
  • Recently, an in vitro study on the expression of ΔF508 CFTR (CFTR which contains a deletion of phenylalanine at position 508) in the ovary cells of Chinese hamsters, which do not express CFTR, revealed a seven-fold increase in the activation of NF-κB compared to the wild-type CFTR or the G551D mutant. (ersjournals.com)
  • Ductal hypertension results in aberrant activation of digestive enzymes from acinar cells. (msdmanuals.com)
  • Hydrolysis of paper moll sludge using an improved enzyme system. (scialert.net)
  • Transient overexpression of UBCv1 impaired activation of NF-κB and AP-1 transcription factors induced by several agonists of these pathways. (mdpi.com)
  • As reported in the news article, while Dr Baker - who is a co-author in the current study - and his team succeeded in designing enzymes for the MBH reaction, these enzymes acted weakly. (europa.eu)
  • This study is the first to test the benefits of blocking this enzyme in reducing the neurological damage caused by brain hypoxia-ischemia. (news-medical.net)
  • In human lung tumors, combined activation of K-RAS and inactivation of RASSF1A is closely associated with the development of the most aggressive and worst prognosis tumors. (cancerindex.org)
  • The new method permits to provide higher yield of the reaction product and select the enzyme most stable to the particular conditions of a certain process. (scialert.net)
  • Product No. 5051S9 S9 Activation Enzymes (SOS-ChromoTest Kit). (biotoxicity.com)
  • As a product is released, the enzyme reverts to its original structure. (lecturio.de)
  • The enzyme releases the product. (meltingpointathens.com)
  • This means that you can make dietary changes that help activate or preserve the enzymes that detoxify common harmful chemicals or deactivate or prevent the creation of the enzymes that "pretoxify" harmless substances into toxic forms. (naturalnews.com)
  • once activated, this causes a series of events that result in an inflammatory response, including plasma extravasation, leukocyte recruitment, and release of degradative enzymes and activation of the coagulation cascade. (medscape.com)
  • Sequential activation of those enzymes allows the circuits to count events happening inside a cell. (sciencedaily.com)
  • FP induces apoptosis of eosinophils 18 and also reduces the production of several cytokines such as IL-1β, IL-6, IL-8 and RANTES (regulated on activation, T-cell expressed and secreted) by alveolar macrophages 19 and lymphocytes 20 , 21 . (ersjournals.com)
  • In response to vascular injury, circulating platelets adhere, aggregate, and provide cell surface phospholipids for the assembly of blood clotting enzyme complexes, thrombin activation, and fibrin formation. (medscape.com)
  • The liver sustains a neutral pH of about 7, which creates the best environment for catalase and other enzymes. (meltingpointathens.com)