Physiologically inactive substances that can be converted to active enzymes.
Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification, such as cleavage, to produce the active functional protein or peptide hormone.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
Inhibitors of HIV PROTEASE, an enzyme required for production of proteins needed for viral assembly.
An HIV protease inhibitor that works by interfering with the reproductive cycle of HIV. It also inhibits CYTOCHROME P-450 CYP3A.
Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.
The rate dynamics in chemical or physical systems.

Caspase 3 inactivation to suppress Fas-mediated apoptosis: identification of binding domain with p21 and ILP and inactivation machinery by p21. (1/3354)

The death mediator caspase acts as the dominant regulator during cell death induction. The CPP32 subfamily, including caspase 3 (CPP32/Yama/Apopain), is essential for the cell death signaling. We recently reported that activation of caspase 3 is regulated by complex formation with p21 or ILP. In the present study, we investigated the binding domain with p21 and ILP to further characterize the caspase 3 inactivation machinery. Our results show that caspase 3 contains p21 binding domain in the N-terminus and ILP binding domain in the active site. Further, the caspase 3 binding domain in p21 was independent of the Cdk- or PCNA-binding domain. We also found caspase 3 protection by p21 from the p3-site cleavage serineproteinase contributes to the suppression machinery. Here, we propose the caspase 3 inactivation system by p21 and ILP as new essential system in the regulation of cell death.  (+info)

Structural basis of profactor D activation: from a highly flexible zymogen to a novel self-inhibited serine protease, complement factor D. (2/3354)

The crystal structure of profactor D, determined at 2.1 A resolution with an Rfree and an R-factor of 25.1 and 20.4%, respectively, displays highly flexible or disordered conformation for five regions: N-22, 71-76, 143-152, 187-193 and 215-223. A comparison with the structure of its mature serine protease, complement factor D, revealed major conformational changes in the similar regions. Comparisons with the zymogen-active enzyme pairs of chymotrypsinogen, trypsinogen and prethrombin-2 showed a similar distribution of the flexible regions. However, profactor D is the most flexible of the four, and its mature enzyme displays inactive, self-inhibited active site conformation. Examination of the surface properties of the N-terminus-binding pocket indicates that Ile16 may play the initial positioning role for the N-terminus, and Leu17 probably also helps in inducing the required conformational changes. This process, perhaps shared by most chymotrypsinogen-like zymogens, is followed by a factor D-unique step, the re-orientation of an external Arg218 to an internal position for salt-bridging with Asp189, leading to the generation of the self-inhibited factor D.  (+info)

BLNK required for coupling Syk to PLC gamma 2 and Rac1-JNK in B cells. (3/3354)

Signaling through the B cell receptor (BCR) is essential for B cell function and development. Despite the key role of Syk in BCR signaling, little is known about the mechanism by which Syk transmits downstream effectors. BLNK (B cell LiNKer protein), a substrate for Syk, is now shown to be essential in activating phospholipase C (PLC)gamma 2 and JNK. The BCR-induced PLC gamma 2 activation, but not the JNK activation, was restored by introduction of PLC gamma 2 membrane-associated form into BLNK-deficient B cells. As JNK activation requires both Rac1 and PLC gamma 2, our results suggest that BLNK regulates the Rac1-JNK pathway, in addition to modulating PLC gamma 2 localization.  (+info)

An alternative transcript of the rat renin gene can result in a truncated prorenin that is transported into adrenal mitochondria. (4/3354)

Characterization of the local renin-angiotensin system in the rat adrenal zona glomerulosa indicated a dual targeting of renin both to the secretory pathway and mitochondria. To investigate the transport of renin into mitochondria, we constructed a series of amino-terminal deletion variants of preprorenin. One of these variants, lacking the complete signal sequence for the endoplasmic reticulum and 10 amino acids of the profragment, was transported efficiently into isolated mitochondria. The transport was further shown to be dependent on mitochondrial membrane potential and ATP synthesis. Analysis of adrenal RNA revealed the existence of 2 renin transcripts. While one of the transcripts corresponds to the known full-length transcript, the other one lacks exon 1; instead, exon 2 is preceded by a domain of 80 nucleotides originating from intron 1. This domain, as well as the following region of intron 1 being excised, shows all essential sequence elements defining an additional, so-far-unknown exon. The second mRNA possibly derives from an additional transcription start in intron 1 and an alternative splicing process. Translation of this mRNA could result in a truncated prorenin representing a cytosolic form of renin, which is required for transport into mitochondria. This truncated prorenin corresponds exactly to the deletion variant being imported into mitochondria in vitro.  (+info)

Tyrosine phosphorylation of SLP-76 is downstream of Syk following stimulation of the collagen receptor in platelets. (5/3354)

Collagen-related peptide (CRP), a collagen homologue, induces platelet activation through a tyrosine kinase-dependent pathway, leading to sequential tyrosine phosphorylation of Fc receptor (FcR) gamma-chain, Syk, and phospholipase C-gamma2. Here we report that CRP and the platelet low affinity immune receptor FcgammaRIIA stimulate tyrosine phosphorylation of the T cell adapter SLP-76, whereas the G protein-coupled receptor agonist thrombin induces only minor tyrosine phosphorylation. This suggests that SLP-76 has a specific role downstream of receptors that signal via an immunoreceptor tyrosine-based activation motif. Immunoprecipitation studies demonstrate association of SLP-76 with SLAP-130, Vav, Fyn, Lyn, and the FcR gamma-chain in CRP-stimulated platelets. Several of these proteins, including SLP-76, undergo tyrosine phosphorylation in in vitro kinase assays performed on SLP-76 immunoprecipitates. Tyrosine phosphorylation of all of these proteins in the in vitro kinase assay was abrogated by the Src family kinase inhibitor PP1, suggesting that it is mediated by either Fyn or Lyn. The physiological significance of this is uncertain, however, since tyrosine phosphorylation of SLP-76 in vivo is not altered in either Fyn- or Lyn-deficient platelets. CRP stimulation of Syk-deficient platelets demonstrated that in vivo tyrosine phosphorylation of SLP-76 is downstream of Syk. The absence of Syk in the SLP-76 immunoprecipitates raises the possibility that another protein is responsible for bringing SLP-76 to Syk. Candidates for this include those proteins that co-immunoprecipitate with SLP-76, including the FcR gamma-chain. Tyrosine phosphorylation of PLC-gamma2 and Ca2+ mobilization is markedly attenuated in SLP-76-deficient platelets following CRP stimulation, suggesting that the adapter plays a critical role in the regulation of the phospholipase. The increase in tyrosine phosphorylation of SLAP-130 in response to CRP is also inhibited in SLP-76-deficient platelets, placing it downstream of SLP-76. This work identifies SLP-76 as an important adapter molecule that is regulated by Syk and lies upstream of SLAP-130 and PLC-gamma2 in CRP-stimulated platelets.  (+info)

Expression and tissue localization of membrane-type 1, 2, and 3 matrix metalloproteinases in human astrocytic tumors. (6/3354)

Three different membrane-type matrix metalloproteinases (MT1-, MT2-, and MT3-MMPs) are known to activate in vitro the zymogen of MMP-2 (pro-MMP-2, progelatinase A), which is one of the key MMPs in invasion and metastasis of various cancers. In the present study, we have examined production and activation of pro-MMP-2, expression of MT1-, MT2-, and MT3-MMPs and their correlation with pro-MMP-2 activation, and localization of MMP-2, MT1-MMP, and MT2-MMP in human astrocytic tumors. The sandwich enzyme immunoassay demonstrates that the production levels of pro-MMP-2 in the anaplastic astrocytomas and glioblastomas are significantly higher than that in the low-grade astrocytomas (P<0.05 and P<0.01, respectively), metastatic brain tumors (P<0.05), or normal brains (P<0.01). Gelatin zymography indicates that the pro-MMP-2 activation ratio is significantly higher in the glioblastomas than in other astrocytic tumors (P<0.01), metastatic brain tumors (P<0.01), and normal brains (P<0.01). The quantitative reverse transcription polymerase chain reaction analyses demonstrate that MT1-MMP and MT2-MMP are expressed predominantly in glioblastoma tissues (17/17 and 12/17 cases, respectively), and their expression levels increase significantly as tumor grade increases. MT3-MMP is detectable in both astrocytic tumor and normal brain tissues, but the mean expression level is approximately 50-fold lower compared with that of MT1-MMP and MT2-MMP in the glioblastomas. The activation ratio of pro-MMP-2 correlates directly with the expression levels of MT1-MMP and MT2-MMP but not MT3-MMP. In situ hybridization indicates that neoplastic astrocytes express MT1-MMP and MT2-MMP in the glioblastoma tissues (5/5 cases and 5/5 cases, respectively). Immunohistochemically, MT1-MMP and MT2-MMP are localized to the neoplastic astrocytes in glioblastoma samples (17/17 cases and 12/17 cases, respectively), which are also positive for MMP-2. In situ zymography shows gelatinolytic activity in the glioblastoma tissues but not in the normal brain tissues. These results suggest that both MT1-MMP and MT2-MMP play a key role in the activation of pro-MMP-2 in the human malignant astrocytic tumors and that the gelatinolytic activity is involved in the astrocytic tumor invasion.  (+info)

Efficient binding of regulated secretory protein aggregates to membrane phospholipids at acidic pH. (7/3354)

Some regulated secretory proteins are thought to be targeted to secretory granules through an acidic-dependent aggregation in the trans-Golgi network. In this report we use pancreatic zymogens, a paradigm of regulated proteins, to test this hypothesis, because they qualitatively aggregate upon acidification in vitro. Pig zymogens were found to start to aggregate significantly at pH approximately 6.0, a pH slightly lower than that at which rat zymogens aggregate, but still compatible with the pH of the cell-sorting compartments. When pig zymogen granule membranes were mixed with the zymogens in the aggregation assay, membranes that normally floated on 1 M sucrose were observed to be pelleted by the aggregating zymogens. Rat membranes were pelleted by pig zymogens and vice versa. Igs, typical constitutively secreted proteins, which needed chemical cross-linking to serve as an aggregated protein control, pelleted membranes almost independently of pH. Corresponding cross-linked zymogen-binding ability and pH dependence was unaffected by the chemical modification. Membranes treated with sodium carbonate, pH 11, or with protease K, were still pelleted by zymogens, suggesting that the aggregated zymogens bound to membrane lipids. This hypothesis was confirmed by the efficient pelleting of unilamellar vesicles composed of granule membrane lipids. Vesicles composed of single classes of phospholipids were also pelleted, but with various efficacies. We conclude that pancreatic zymogen aggregates, formed under the acidic conditions of the secretory pathway sorting compartments, have the capacity to bind firmly to membranes through their phospholipid constituents.  (+info)

Phosphatidylinositol 3-kinase and protein kinase C are required for the inhibition of caspase activity by epidermal growth factor. (8/3354)

The mechanism by which growth factors exert an anti-apoptotic function on many cell types is not well understood. This issue is addressed in relation to epidermal growth factor (EGF) which inhibits apoptosis induced by staurosporine or wortmannin in an epithelial tumour cell line (CNE-2). The presence of EGF substantially reduced the in vitro Ac-DEVD-AMC hydrolytic activity and almost completely suppressed the intracellular cleavage of poly(ADP-ribose) polymerase in staurosporine- or wortmannin-treated cells. Staurosporine but not wortmannin caused the intracellular proteolytic processing of pro-caspase-3 and this event was transiently inhibited by EGF. Staurosporine-induced apoptosis was not inhibited by EGF in the presence of wortmannin or LY294002. Similarly, EGF failed to inhibit wortmannin-induced apoptosis in the presence of staurosporine, chelerythrine chloride or Go6850. These results suggest that phosphatidylinositol 3-kinase and protein kinase C play a role in the survival function of EGF but the reduction of cellular caspase activity cannot be satisfactorily explained by a lack of pro-caspase-3 activation.  (+info)

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.

Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification to become active. These modifications typically include cleavage of the precursor protein by specific enzymes, resulting in the release of the active protein. This process allows for the regulation and control of protein activity within the body. Protein precursors can be found in various biological processes, including the endocrine system where they serve as inactive hormones that can be converted into their active forms when needed.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

Angiotensin-Converting Enzyme (ACE) inhibitors are a class of medications that are commonly used to treat various cardiovascular conditions, such as hypertension (high blood pressure), heart failure, and diabetic nephropathy (kidney damage in people with diabetes).

ACE inhibitors work by blocking the action of angiotensin-converting enzyme, an enzyme that converts the hormone angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor, meaning it narrows blood vessels and increases blood pressure. By inhibiting the conversion of angiotensin I to angiotensin II, ACE inhibitors cause blood vessels to relax and widen, which lowers blood pressure and reduces the workload on the heart.

Some examples of ACE inhibitors include captopril, enalapril, lisinopril, ramipril, and fosinopril. These medications are generally well-tolerated, but they can cause side effects such as cough, dizziness, headache, and elevated potassium levels in the blood. It is important for patients to follow their healthcare provider's instructions carefully when taking ACE inhibitors and to report any unusual symptoms or side effects promptly.

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.

HIV Protease Inhibitors are a class of antiretroviral medications used in the treatment of HIV infection. They work by blocking the activity of the HIV protease enzyme, which is necessary for the virus to replicate and infect new cells. By inhibiting this enzyme, the medication prevents the virus from maturing and assembling into new infectious particles.

HIV protease inhibitors are often used in combination with other antiretroviral drugs as part of a highly active antiretroviral therapy (HAART) regimen. This approach has been shown to effectively suppress viral replication, reduce the amount of virus in the bloodstream (viral load), and improve the health and longevity of people living with HIV.

Examples of HIV protease inhibitors include saquinavir, ritonavir, indinavir, nelfinavir, amprenavir, fosamprenavir, atazanavir, darunavir, and tipranavir. These medications are usually taken orally in the form of tablets or capsules, and may be prescribed alone or in combination with other antiretroviral drugs.

It is important to note that HIV protease inhibitors can have significant side effects, including gastrointestinal symptoms such as nausea, diarrhea, and abdominal pain, as well as metabolic changes such as increased cholesterol and triglyceride levels. Therefore, regular monitoring of liver function, lipid levels, and other health parameters is necessary to ensure safe and effective use of these medications.

Ritonavir is an antiretroviral medication used in the treatment and prevention of HIV/AIDS. It is a protease inhibitor, which works by blocking the action of protease, an enzyme that the virus needs to multiply. By doing this, Ritonavir helps to reduce the amount of HIV in the body, keeping it at a low level and preventing the disease from progressing.

Ritonavir is often used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART). It is also sometimes used at lower doses to boost the levels of other protease inhibitors in the body, a practice known as "pharmacologic boosting."

It's important to note that Ritonavir does not cure HIV/AIDS, but it can help people with HIV live longer, healthier lives. As with all medications, Ritonavir can have side effects, and it may interact with other drugs, so it's important to take it exactly as prescribed by a healthcare provider.

Enzymes are complex proteins that act as catalysts to speed up chemical reactions in the body. They help to lower activation energy required for reactions to occur, thereby enabling the reaction to happen faster and at lower temperatures. Enzymes work by binding to specific molecules, called substrates, and converting them into different molecules, called products. This process is known as catalysis.

Enzymes are highly specific and will only catalyze one particular reaction with a specific substrate. The shape of the enzyme's active site, where the substrate binds, determines this specificity. Enzymes can be regulated by various factors such as temperature, pH, and the presence of inhibitors or activators. They play a crucial role in many biological processes, including digestion, metabolism, and DNA replication.

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.

Enzyme precursors are called zymogens or proenzymes. Examples are enzymes of the digestive tract in humans. Some protein ... A protein precursor, also called a pro-protein or pro-peptide, is an inactive protein (or peptide) that can be turned into an ... Protein precursors are often used by an organism when the subsequent protein is potentially harmful, but needs to be available ... Media related to Precursor proteins at Wikimedia Commons v t e (Articles with short description, Short description matches ...
Gluschankof P, Gomez S, Morel A, Cohen P (July 1987). "Enzymes that process somatostatin precursors. A novel endoprotease that ... Nardilysin (EC 3.4.24.61, N-arginine dibasic convertase, NRD-convertase) is an enzyme. This enzyme catalyses the following ... in which Xaa is not Arg or Lys This enzyme is present rat brain and testis. Gomez S, Gluschankof P, Morel A, Cohen P (September ... a metalloendopeptidase as a prototype of a class of processing enzymes". Proceedings of the National Academy of Sciences of the ...
Protein precursor Zymogen Braun P, de Groot A, Bitter W, Tommassen J (1988). "Secretion of elastinolytic enzymes and their ... which directs the enzyme to a specific organelle or subcellular localization; "pro" indicates that the enzyme is present in an ... A preproenzyme is an enzyme with two additional characteristics: "pre" refers to a signal sequence (signal peptide) ...
Zymogens are the usually inactive precursors of an enzyme. If the digestive enzymes were active when synthesized, they would ... preventing the enzyme from working properly. Trypsin, a powerful digestive enzyme, is generated in the pancreas. Inhibitors ... These enzymes can be further categorised based on their substrate specificity as either trypsin-like, chymotrypsin-like or ... The triad is located in the active site of the enzyme, where catalysis occurs, and is preserved in all superfamilies of serine ...
Mature microRNAs are processed from the precursor stem-loop by the Dicer enzyme. In this case, the mature sequence is excised ... In molecular biology, miR-130 microRNA precursor is a small non-coding RNA that regulates gene expression. This microRNA has ... Page for mir-130 microRNA precursor family at Rfam miRBase family MIPF0000034 v t e (GO template errors, MicroRNA, MicroRNA ... precursor families, All stub articles, Molecular and cellular biology stubs). ...
The mature microRNA is processed from the longer hairpin precursor by the Dicer enzyme. In this case, the mature sequence is ... In molecular biology, miR-194 microRNA precursor is a small non-coding RNA gene that regulated gene expression. Its expression ... Page for mir-194 microRNA precursor family at Rfam miRBase family MIPF0000055 v t e (GO template errors, MicroRNA, MicroRNA ... precursor families, All stub articles, Molecular and cellular biology stubs). ...
"Molecular forms in human serum of enzymes synthesizing DNA precursors and DNA". Mol. Cell. Biochem. 92 (1): 23-35. doi:10.1007/ ... Such enzymes are called salvage enzymes. Thymidine kinase 1 is such a salvage enzyme, whereas thymidine kinase 2 is not cell ... Thymidine kinase is a salvage enzyme that is only present in anticipation of cell division. The enzyme is not set free from ... The TK enzyme suggested as a tumor marker is the cytosolic cell cycle dependent TK1. It is present during cell division in much ...
"Molecular forms in human serum of enzymes synthesizing DNA precursors and DNA". Molecular and Cellular Biochemistry. 92 (1): 23 ... Such enzymes are called salvage enzymes. Thymidine kinase 1 is such a salvage enzyme, whereas thymidine kinase 2 and ... Thymidine kinase is a salvage enzyme that is only present in anticipation of cell division. The enzyme is not set free from ... The enzyme form in virus is different from that in other organisms. Thymidine kinase is not present in fungi. The first ...
... proteins likely evolved from an amylase enzyme precursor. The two enzymes have similar folding patterns and ... For example, both enzymes have three domains in their catalytic core and a (β/α)8 barrel. Glucansucrase has five major domains ... Bacteria with glucansucrase enzymes are used extensively in industry for a variety of applications. The polymer dextran is one ... Glucansucrase enzymes can synthesize a variety of glucans with differing solubilities, rheology, and other properties by ...
Pepsinogen is a precursor enzyme (zymogen) produced by the gastric chief cells, and gastric acid activates this to the enzyme ... The precursor zymogens, are inactive variants of the enzymes; which avoids the onset of pancreatitis caused by autodegradation ... The cells are filled with secretory granules containing the precursor digestive enzymes. The major proteases, the pancreatic ... The digestive enzymes in saliva also help in keeping the teeth clean by breaking down any lodged food particles. The epiglottis ...
miRNAs come from hairpin precursors generated by the RNaseIII enzymes Drosha and Dicer. Both miRNA and siRNA form either the ... Zeng Y, Yi R, Cullen BR (Jan 2005). "Recognition and cleavage of primary microRNA precursors by the nuclear processing enzyme ... siRNAs come from long dsRNA precursors derived from a variety of single-stranded RNA (ssRNA) precursors, such as sense and ... siRNAs may also arise enzymatically from non-coding RNA precursors. The volume of literature on siRNA within the framework of ...
"Recognition and cleavage of primary microRNA precursors by the nuclear processing enzyme Drosha". The EMBO Journal. 24 (1): 138 ... Drosha is a Class 2 ribonuclease III enzyme that in humans is encoded by the DROSHA (formerly RNASEN) gene. It is the primary ... The other two human enzymes that participate in the processing and activity of miRNA are the Dicer and Argonaute proteins. ... Drosha and other miRNA processing enzymes may be important in cancer prognosis. Both Drosha and Dicer can function as master ...
To increase the production of alcohol precursors, five isobutanol pathway enzymes were overexpressed. Increase in the demand ... metagenics is the practice of engineering organisms to create a specific enzyme, protein, or other biochemicals from simpler ...
The ME3 gene stands for mitochondrial malic enzyme 3 precursor. Malic enzyme catalyzes the oxidative decarboxylation of malate ... Mammalian tissues contain 3 distinct isoforms of malic enzyme: a cytosolic NADP(+)-dependent isoform, a mitochondrial NADP(+)- ...
... lysosomal enzyme precursor acetylglucosamine-1-phosphotransferase, UDP-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-1 ... Waheed A, Hasilik A, von Figura K (1982). "UDP-N-acetylglucosamine:lysosomal enzyme precursor N-acetylglucosamine-1- ... Proposed enzyme for the phosphorylation of the high mannose oligosaccharide units of lysosomal enzymes". J. Biol. Chem. 256 (9 ... The systematic name of this enzyme class is UDP-N-acetyl-D-glucosamine:lysosomal-enzyme N-acetylglucosaminephosphotransferase. ...
The B complex vitamins function as enzyme cofactors (coenzymes) or the precursors for them. Vitamins C and E function as ... In 1930, Paul Karrer elucidated the correct structure for beta-carotene, the main precursor of vitamin A, and identified other ... Humans can produce some vitamins from precursors they consume: for example, vitamin A is synthesized from beta carotene; and ... Pyrithiamine, a synthetic compound, has a molecular structure similar to thiamine, vitamin B1, and inhibits the enzymes that ...
The enzymes were then mixed with the precursor and the mutant enzymes that produced the greatest amount of didanosine were ... The enzyme "optimizations" that increase the production of one precursor from another are cumulative in that the same precursor ... The first step was repeated, using the first precursor in place of didanosine, finding a yet simpler precursor and an enzyme to ... For each precursor, the enzyme is evolved using induced mutations and natural selection to produce a more productive version. ...
Other blood proteins act as enzymes, complement components, protease inhibitors or kinin precursors. Contrary to popular belief ... The remainder of the plasma proteins (1%) are regulatory proteins, such as enzymes, proenzymes, and hormones. All blood ...
The digestive enzymes however are mostly secreted as their inactive precursors, the zymogens. For example, trypsin is secreted ... In chemical digestion, enzymes break down food into the small compounds that the body can use. In the human digestive system, ... Most digestive enzymes are sensitive to pH and will denature in a high or low pH environment. The stomach's high acidity ... Sucrase is an enzyme that breaks down the disaccharide sucrose, commonly known as table sugar, cane sugar, or beet sugar. ...
Teixobactin also seemed to be specifically involved with peptidoglycan precursors rather than blocking enzyme activity. Ling LL ... have shown teixobactin is capable of binding to lipid precursors of peptidoglycan, which makes up part of bacterial cell walls ... a similar mechanism of action as the antibiotic vancomycin that binds to the lipid II molecule in peptidoglycan precursors but ...
These enzymes are synthesized as precursors or propeptides, which cleave themselves by an autoproteolytic reaction. The self- ... Proteolytic enzymes are classified into families based on sequence similarity. Each family includes proteolytic enzymes with ... However, the self-processing is the action of a proteolytic enzyme, notwithstanding the enzyme is not recoverable from the ... Handbook of Proteolytic Enzymes. Third edition. (2013) (pp. 14-16) Rawlings ND, Barrett AJ, Bateman A. Asparagine peptide ...
He named the hypothetical enzyme "thrombin", and he called its precursor "prothrombin". Schmidt is credited for providing a ...
"The CRISPR-associated DNA-cleaving enzyme Cpf1 also processes precursor CRISPR RNA". Nature. 532 (7600): 517-521. Bibcode: ...
"The CRISPR-associated DNA-cleaving enzyme Cpf1 also processes precursor CRISPR RNA". Nature. 532 (7600): 517-521. Bibcode: ... RNA-guided CRISPR enzymes are classified as type V restriction enzymes. The cas genes in the adaptor and effector modules of ... Cas9 enzymes together with CRISPR sequences form the basis of a technology known as CRISPR-Cas9 that can be used to edit genes ... Cas9 (or "CRISPR-associated protein 9") is an enzyme that uses CRISPR sequences as a guide to recognize and open up specific ...
"The CRISPR-associated DNA-cleaving enzyme Cpf1 also processes precursor CRISPR RNA". Nature. 532 (7600): 517-521. Bibcode: ... The CRISPR-Cas12a system consist of a Cas12a enzyme and a guide RNA that finds and positions the complex at the correct spot on ... Two candidate enzymes from Acidaminococcus and Lachnospiraceae display efficient genome-editing activity in human cells. A ... Articles with short description, Short description is different from Wikidata, Genetic engineering, Enzymes, Genome editing). ...
... for high content of the enzyme amino acid decarboxylase (for conversion of precursors to amines). Adenohypophysis Neurons of ... The name is derived from an acronym, referring to the following: Amine Precursor Uptake - for high uptake of amine precursors ...
Bacteria use a similar enzyme (shc) to create the pentacyclic hopanoid precursor, diploptene; however, this biosynthesis does ... Eukaryotes use oxidosqualene cyclase and several other enzymes to create the tetracyclic skeleton found in steroids, a process ... Ten Haven HL, Rohmer M, Rullkötter J, Bisseret P (November 1989). "Tetrahymanol, the most likely precursor of gammacerane, ...
Yamin TT, Ayala JM, Miller DK (May 1996). "Activation of the native 45-kDa precursor form of interleukin-1-converting enzyme". ... Once active, the inflammasome binds to pro-caspase-1 (the precursor molecule of caspase-1), either homotypically via its own ... January 1997). "Activation of interferon-gamma inducing factor mediated by interleukin-1beta converting enzyme". Science. 275 ( ... inhibition of glycolytic enzymes, activation of lipid biosynthesis and secretion of tissue-repair mediators such as pro-IL-1α. ...
leucoanthocyanidin dioxygenase). In petunia, the DFR enzyme does not react with the simplest precursor (dihydrokaempferol); ... by two enzymes, flavonoid 3'hydroxylase (F3'H) and flavonoid 3'5'hydroxylase (F3'5'H). The enzyme dihydroflavonol reductase ( ... is an example of substrate specificity of one enzyme limiting the spectrum of possible products of the pathway. Anthocyanins ...
... a vacuolar enzyme required for processing of vacuolar precursors". Molecular and Cellular Biology. 6 (7): 2490-9. doi:10.1128/ ... is an enzyme. This enzyme catalyses the following chemical reaction Hydrolysis of proteins with broad specificity for peptide ... This enzyme is present in baker's yeast (Saccharomyces cerevisiae). Proteinase A is an aspartic proteinase found in ...
Spirocyclic Beta-Site Amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) Inhibitors ... Spirocyclic beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors: from hit to lowering of cerebrospinal ... Spirocyclic Beta-Site Amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) Inhibitors. *PDB DOI: https://doi.org/10.2210/pdb4JP9 ...
And whats really different about this enzyme, compared to all other enzymes people have studied, is that this enzyme is ... Reconstitution of Enzyme Synthesizing Lovastatin Precursor. November 3, 2009. Researchers from UCLA, and colleagues, have for ... "Its one of the largest enzymes ever to be reconstituted in a test tube. It is ten times the size of most enzymes people study ... "In this study, we studied the enzyme that makes a small-molecule precursor to lovastatin. ...
Methyl-removing enzyme diverts toxin precursor. Gut bacteria can produce harmful compounds as a byproduct of their normal ... Seeking to identify the enzymes involved in this metabolic transformation, Kountz noticed that E. limosum encoded many enzymes ... Kountz characterized the enzymes involved in this pathway and identified a methyltransferase, MtcB, that demethylates carnitine ... The Krzycki lab was finishing a project on an enzyme belonging to a superfamily of methyltransferases, and Kountz wanted to ...
Enzyme precursors are called zymogens or proenzymes. Examples are enzymes of the digestive tract in humans. Some protein ... A protein precursor, also called a pro-protein or pro-peptide, is an inactive protein (or peptide) that can be turned into an ... Protein precursors are often used by an organism when the subsequent protein is potentially harmful, but needs to be available ... Media related to Precursor proteins at Wikimedia Commons v t e (Articles with short description, Short description matches ...
... was obtained and the immobilized enzyme was successfully used in sequential batch reactor operation with enzyme reactivation ... was obtained and the immobilized enzyme was successfully used in sequential batch reactor operation with enzyme reactivation ... was obtained and the immobilized enzyme was successfully used in sequential batch reactor operation with enzyme reactivation ... was obtained and the immobilized enzyme was successfully used in sequential batch reactor operation with enzyme reactivation ...
The specific activities of certain of the enzymes involved in the formation of the sugar nucleotide precursors of ... The level of enzyme activity did not reflect either the amount of extracellular polysaccharide produced or the rate at which ... Studies on Precursor-forming Enzymes and Factors Affecting Exopolysaccharide Production by Washed Suspensions * A. G. Williams1 ... The specific activities of certain of the enzymes involved in the formation of the sugar nucleotide precursors of ...
... a key regulatory enzyme in the synthetic pathway of eicosanoid production, results in beneficial and detrimental physiologic ... Hence, precursor availability and enzyme kinetics play a key role in the regulation of individual responses. ... Precursors. The eicosanoids, which include prostaglandins, leukotrienes, thromboxanes, and lipoxins, are derived from the ... 1, 10] However, only a fraction of these 20-carbon polyenoic acid precursors are the substrates that actually yield eicosanoids ...
... a key regulatory enzyme in the synthetic pathway of eicosanoid production, results in beneficial and detrimental physiologic ... Hence, precursor availability and enzyme kinetics play a key role in the regulation of individual responses. ... Precursors. The eicosanoids, which include prostaglandins, leukotrienes, thromboxanes, and lipoxins, are derived from the ... 1, 10] However, only a fraction of these 20-carbon polyenoic acid precursors are the substrates that actually yield eicosanoids ...
PyruvateCarboxylase (PC) is a pivotal enzyme to generate lipid precursors. Cellbiological assays identified a long non-coding ( ...
Tumors may produce hormones, hormone precursors, a variety of enzymes, or cytokines. Several cancers produce proteins that are ... Pancreatic tumors can release several lipases and lithic enzymes into the bloodstream, leading to adipose nodular necrosis of ... Dermic melanosis results from melanin precursors that enter the bloodstream and, because they cannot be eliminated completely ... hormone precursors, or hormonelike substances. [13] Cancers generally do not synthesize steroid hormones, except those arising ...
The β-secretase, β-site amyloid precursor protein cleaving enzyme (BACE1; also called Asp2, memapsin 2), is the enzyme ... 2003) Characterization of the ectodomain shedding of the beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1) J Biol ... 2000) Maturation and endosomal targeting of beta-site amyloid precursor protein-cleaving enzyme. The Alzheimers disease beta- ... 2001) Alzheimers beta-secretase, beta-site amyloid precursor protein-cleaving enzyme, is responsible for cleavage secretion of ...
... β-site amyloid precursor protein cleaving enzymes), and IgE (Immunoglobulin E). ... ...
4-NAPE-induced inhibition was blocked by anandamide-synthesizing enzyme N-acyl phosphatidylethanolamine phospholipase D (NAPE- ... The switch between TRPV1 and CB1 receptor activation by the AEA precursor 20:4-NAPE during inflammation may play an important ... We investigated the effect of the anandamide precursor 20:4-NAPE on synaptic activity in naive and inflammatory conditions. ... 4-NAPE-induced inhibition was blocked by anandamide-synthesizing enzyme N-acyl phosphatidylethanolamine phospholipase D (NAPE- ...
Irreversible acetylation of COX-2 by aspirin changes the enzymes product from PGs intermediate to precursors of ATLMs. The ... Cyclooxygenase-2 enzyme inhibitors: place in therapy. Am Fam Physician 2000. 61:3669-3676. View this article via: PubMed Google ... Prostaglandins and their precursors * Series Introduction: COX in a crystal ball: current status and future promise of ... 65 and references therein). With ASA-COX-2, the chirality of the precursor 15R is retained by human PMNs to give 15-epi-LXA5 ( ...
Beta-site APP cleaving enzyme 1 , Beta-site amyloid precursor protein cleaving enzyme 1 , KIAA1149 , Memapsin-2 , Membrane- ...
This enzyme is responsible for the production of a substance called mevalonate . Mevalonate on its turn is the precursor of ... amount of an HMG-CoA reductase inhibitor and an amount of Co-enzyme Q10 effective to couteract HMG-CoA reductase inhibitor- ... both cholesterol and co-enzyme Q10. This Q10 also called ubiquinone because it is involved in myriads of physiological ... Statins block the enzyme HMG CoA-reductase. ...
The APP gene provides instructions for making a protein called amyloid precursor protein. Learn about this gene and related ... Amyloid precursor protein is cut by enzymes to create smaller fragments (peptides), some of which are released outside the cell ... The amyloid precursor protein/protease nexin 2 Kunitz inhibitor domain is a highly specific substrate of mesotrypsin. J Biol ... The most common APP gene variant changes one of the protein building blocks (amino acids) in the amyloid precursor protein. ...
Inhibition by rhodamine 123 and accumulation of enzyme precursors in isolated hepatocytes. Morita, T., Mori, M., Ikeda, F., ... are matrix enzymes synthesized outside the mitochondria in the form of larger precursors and are transported rapidly into ... Carboxyl-terminal sequences influence the import of mitochondrial protein precursors in vivo. Ness, S.A., Weiss, R.L. Proc. ... Synthesis, intracellular transport, and processing of the precursors for mitochondrial ornithine transcarbamylase and carbamoyl ...
Where do heme precursors accumulate in the body?. If one of the essential enzymes in heme production is deficient, certain ... The specific precursors that accumulate depend on which enzyme is deficient. What causes heme to be produced in coproporphyria? ... The specific precursors that accumulate depend on which enzyme is deficient.. Are there any inherited disorders of haemoglobin ... If one of the essential enzymes in heme production is deficient, certain precursors may accumulate in tissues (especially in ...
One of these genes is the Bace1 gene for the β-site amyloid precursor protein-cleaving enzyme 1 (BACE1). Upregulation of BACE1 ... DNA methyltransferases (DNMTs) are enzymes that are responsible for the addition of a methyl group to the C5 cytosine residue ... Phosphoinositide 3-kinases (PI3Ks) are a family of multifaceted enzymes that play a central role in diverse metabolic processes ... The complexities of function require further studies to better understand the specific regulation of different PI3K enzymes in ...
The N‑terminal peptide is cleaved (split) from the zymogen enzyme precursor by another enzyme to release an active enzyme.[8] ... An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical ... Copeland RA (March 2013). "Why Enzymes as Drug Targets? Enzyme are Essential for Life". Evaluation of Enzyme Inhibitors in Drug ... Many drug molecules are enzyme inhibitors that inhibit an aberrant human enzyme or an enzyme critical for the survival of a ...
... carbohydrates distinguished by different monosaccharides added to a precursor oligosaccharide by fucosyltransferase enzymes (23 ... Genetic control of the fucosylation of ABH precursor chains. Evidence for new epistatic interactions in different cells and ... Homozygosity for an enzyme-inactivating nonsense mutation commonly correlates with the non-secretor phenotype. J Biol Chem. ... To determine whether 3-D intestinal aggregates contain the FUT2 gene that converts precursor molecules to H-type antigens (21 ...
Enzyme Precursors * Nitric Oxide Synthase * Nitric Oxide Synthase Type II * Nitric Oxide Synthase Type III ...
That enzyme extends the precursors to form mycocerosic acids that remain attached until transferred by EC 2.3.1.282.. ... The fatty acid precursors of mycocerosic acids are activated by EC 6.2.1.49, long-chain fatty acid adenylyltransferase FadD28, ... The enzyme, present in certain pathogenic species of mycobacteria, catalyses the transfer of mycocerosic acids to the two ...
The enzyme RNA polymerase II synthesizes precursors to mRNAs and small nuclear RNAs. Sequence analysis of the largest subunit ...
... the dye precursors, (2) the dye enzyme (purpurase). The enzyme acts on the precursors upon exposure to oxygen (i.e., when the ... "The enzyme required for dye formation quickly decomposes upon the death of the snail, and so the glands that hold the dye ... would no longer exist to act upon the dye precursors.". The gemara is not a contradiction at all. The time when you are chayav ... precursor must be crushed while the snail is alive or soon after. In experiments, we have seen that as soon as two hours after ...
... theres evidence to suggest that the increase in glutamate involved drug-induced changes in enzymes and glutamate precursors. ...
... can be obtained directly from animal foods or synthesized endogenously from 18 carbon precursors via the FADS2 coded enzyme. ... The biochemical pathway product-precursor difference, arachidonic acid minus linoleic acid, was 31% and 13% greater for I/I and ...
Thesis entitled: beta-Site Amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) as a Novel Alzheimers Disease Intervention ...

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