Incorporation of biotinyl groups into molecules.
A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.
Enzymes that catalyze the joining of two molecules by the formation of a carbon-nitrogen bond. EC 6.3.
An enzyme which catalyzes the release of BIOTIN from biocytin. In human, defects in the enzyme are the cause of the organic acidemia MULTIPLE CARBOXYLASE DEFICIENCY or BIOTINIDASE DEFICIENCY.
A 60-kDa extracellular protein of Streptomyces avidinii with four high-affinity biotin binding sites. Unlike AVIDIN, streptavidin has a near neutral isoelectric point and is free of carbohydrate side chains.
A specific protein in egg albumin that interacts with BIOTIN to render it unavailable to mammals, thereby producing biotin deficiency.
The form of fatty acid synthase complex found in BACTERIA; FUNGI; and PLANTS. Catalytic steps are like the animal form but the protein structure is different with dissociated enzymes encoded by separate genes. It is a target of some ANTI-INFECTIVE AGENTS which result in disruption of the CELL MEMBRANE and CELL WALL.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
A carboxy-lyase that catalyzes the decarboxylation of (S)-2-Methyl-3-oxopropanoyl-CoA to propanoyl-CoA. In microorganisms the reaction can be coupled to the vectorial transport of SODIUM ions across the cytoplasmic membrane.
The neonatal form of MULTIPLE CARBOXYLASE DEFICIENCY that is caused by a defect or deficiency in holocarboxylase synthetase. HLCS is the enzyme that covalently links biotin to the biotin dependent carboxylases (propionyl-CoA-carboxylase, pyruvate carboxylase, and beta-methylcrotonyl-CoA carboxylase).
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
Established cell cultures that have the potential to propagate indefinitely.
A group of enzymes that catalyze the transfer of carboxyl- or carbamoyl- groups. EC 2.1.3.
Enzymes that catalyze the joining of two molecules by the formation of a carbon-carbon bond. These are the carboxylating enzymes and are mostly biotinyl-proteins. EC 6.4.
A carboxylating enzyme that catalyzes the conversion of ATP, acetyl-CoA, and HCO3- to ADP, orthophosphate, and malonyl-CoA. It is a biotinyl-protein that also catalyzes transcarboxylation. The plant enzyme also carboxylates propanoyl-CoA and butanoyl-CoA (From Enzyme Nomenclature, 1992) EC 6.4.1.2.
The turning off of GENETIC TRANSCRIPTION in certain regions of CHROMATIN without changes in the DNA sequence. Typically epigenetic repression is a way that developmental changes are programmed at the cellular level.
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.
A deficiency in the activities of biotin-dependent enzymes (propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, and PYRUVATE CARBOXYLASE) due to one of two defects in BIOTIN metabolism. The neonatal form is due to HOLOCARBOXYLASE SYNTHETASE DEFICIENCY. The late-onset form is due to BIOTINIDASE DEFICIENCY.
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.
A cytosolic carbonic anhydrase isoenzyme primarily expressed in ERYTHROCYTES, vascular endothelial cells, and the gastrointestinal mucosa. EC 4.2.1.-
Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.
An essential amino acid. It is often added to animal feed.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
A subclass of IMIDES with the general structure of pyrrolidinedione. They are prepared by the distillation of ammonium succinate. They are sweet-tasting compounds that are used as chemical intermediates and plant growth stimulants.
A biotin-dependent enzyme belonging to the ligase family that catalyzes the addition of CARBON DIOXIDE to pyruvate. It is occurs in both plants and animals. Deficiency of this enzyme causes severe psychomotor retardation and ACIDOSIS, LACTIC in infants. EC 6.4.1.1.
Membrane transporters that co-transport two or more dissimilar molecules in the same direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Proteins obtained from ESCHERICHIA COLI.
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 movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.
Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
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 chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
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.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
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.
The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.
The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.
Anaerobic hyperthermophilic species of ARCHAEA, isolated from hydrothermal fluid samples. It is obligately heterotrophic with coccoid cells that require TRYPTOPHAN for growth.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
A family of plasma membrane neurotransmitter transporter proteins that couple the uptake of GLUTAMATE with the import of SODIUM ions and PROTONS and the export of POTASSIUM ions. In the CENTRAL NERVOUS SYSTEM they regulate neurotransmission through synaptic reuptake of the excitatory neurotransmitter glutamate. Outside the central nervous system they function as signal mediators and regulators of glutamate metabolism.
Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of Bellini) which opens on the summit of the papilla.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.
Transport proteins that carry specific substances in the blood or across cell membranes.
Na-K-Cl transporter in the ASCENDING LIMB OF LOOP OF HENLE. It mediates active reabsorption of sodium chloride and is inhibited by LOOP DIURETICS such as FUROSEMIDE; and BUMETANIDE. Mutations in the gene encoding SLC12A1 are associated with a BARTTER SYNDROME.
Sodium channels found on salt-reabsorbing EPITHELIAL CELLS that line the distal NEPHRON; the distal COLON; SALIVARY DUCTS; SWEAT GLANDS; and the LUNG. They are AMILORIDE-sensitive and play a critical role in the control of sodium balance, BLOOD VOLUME, and BLOOD PRESSURE.
A genus of gram-positive, rod-shaped bacteria whose cells occur singly, in pairs or short chains, in V or Y configurations, or in clumps resembling letters of the Chinese alphabet. Its organisms are found in cheese and dairy products as well as on human skin and can occasionally cause soft tissue infections.
A genus of microaerophilic, gram-negative bacteria that forms crystals of the mineral magnetite in special organelles called MAGNETOSOMES.
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.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
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 parts of a macromolecule that directly participate in its specific combination with another molecule.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.
A CELL LINE derived from human T-CELL LEUKEMIA and used to determine the mechanism of differential susceptibility to anti-cancer drugs and radiation.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
A chloride channel that regulates secretion in many exocrine tissues. Abnormalities in the CFTR gene have been shown to cause cystic fibrosis. (Hum Genet 1994;93(4):364-8)
Proteins prepared by recombinant DNA technology.
New World marsupials of the family Didelphidae. Opossums are omnivorous, largely nocturnal and arboreal MAMMALS, grow to about three feet in length, including the scaly prehensile tail, and have an abdominal pouch in which the young are carried at birth.
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of dopaminergic neurons. They remove DOPAMINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS and are the target of DOPAMINE UPTAKE INHIBITORS.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
Human colonic ADENOCARCINOMA cells that are able to express differentiation features characteristic of mature intestinal cells, such as ENTEROCYTES. These cells are valuable in vitro tools for studies related to intestinal cell function and differentiation.
A fungal metabolite which is a macrocyclic lactone exhibiting a wide range of antibiotic activity.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
Proteins found in any species of bacterium.

A single membrane-embedded negative charge is critical for recognizing positively charged drugs by the Escherichia coli multidrug resistance protein MdfA. (1/1806)

The nature of the broad substrate specificity phenomenon, as manifested by multidrug resistance proteins, is not yet understood. In the Escherichia coli multidrug transporter, MdfA, the hydrophobicity profile and PhoA fusion analysis have so far identified only one membrane-embedded charged amino acid residue (E26). In order to determine whether this negatively charged residue may play a role in multidrug recognition, we evaluated the expression and function of MdfA constructs mutated at this position. Replacing E26 with the positively charged residue lysine abolished the multidrug resistance activity against positively charged drugs, but retained chloramphenicol efflux and resistance. In contrast, when the negative charge was preserved in a mutant with aspartate instead of E26, chloramphenicol recognition and transport were drastically inhibited; however, the mutant exhibited almost wild-type multidrug resistance activity against lipophilic cations. These results suggest that although the negative charge at position 26 is not essential for active transport, it dictates the multidrug resistance character of MdfA. We show that such a negative charge is also found in other drug resistance transporters, and its possible significance regarding multidrug resistance is discussed.  (+info)

Comparison of the backbone dynamics of the apo- and holo-carboxy-terminal domain of the biotin carboxyl carrier subunit of Escherichia coli acetyl-CoA carboxylase. (2/1806)

The biotin carboxyl carrier protein (BCCP) is a subunit of acetyl-CoA carboxylase, a biotin-dependent enzyme that catalyzes the first committed step of fatty acid biosynthesis. In its functional cycle, this protein engages in heterologous protein-protein interactions with three distinct partners, depending on its state of post-translational modification. Apo-BCCP interacts specifically with the biotin holoenzyme synthetase, BirA, which results in the post-translational attachment of biotin to a single lysine residue on BCCP. Holo-BCCP then interacts with the biotin carboxylase subunit of acetyl-CoA carboxylase, which leads to the addition of the carboxylate group of bicarbonate to biotin. Finally, the carboxy-biotinylated form of BCCP interacts with transcarboxylase in the transfer of the carboxylate to acetyl-CoA to form malonyl-CoA. The determinants of protein-protein interaction specificity in this system are unknown. The NMR solution structure of the unbiotinylated form of an 87 residue C-terminal domain fragment (residue 70-156) of BCCP (holoBCCP87) and the crystal structure of the biotinylated form of a C-terminal fragment (residue 77-156) of BCCP from Escherichia coli acetyl-CoA carboxylase have previously been determined. Comparative analysis of these structures provided evidence for small, localized conformational changes in the biotin-binding region upon biotinylation of the protein. These structural changes may be important for regulating specific protein-protein interactions. Since the dynamic properties of proteins are correlated with local structural environments, we have determined the relaxation parameters of the backbone 15N nuclear spins of holoBCCP87, and compared these with the data obtained for the apo protein. The results indicate that upon biotinylation, the inherent mobility of the biotin-binding region and the protruding thumb, with which the biotin group interacts in the holo protein, are significantly reduced.  (+info)

Streptavidin facilitates internalization and pulmonary targeting of an anti-endothelial cell antibody (platelet-endothelial cell adhesion molecule 1): a strategy for vascular immunotargeting of drugs. (3/1806)

Conjugation of drugs with antibodies to surface endothelial antigens is a potential strategy for drug delivery to endothelium. We studied antibodies to platelet-endothelial adhesion molecule 1 (PECAM-1, a stably expressed endothelial antigen) as carriers for vascular immunotargeting. Although 125I-labeled anti-PECAM bound to endothelial cells in culture, the antibody was poorly internalized by the cells and accumulated poorly after intravenous administration in mice and rats. However, conjugation of biotinylated anti-PECAM (b-anti-PECAM) with streptavidin (SA) markedly stimulated uptake and internalization of anti-PECAM by endothelial cells and by cells expressing PECAM. In addition, conjugation with streptavidin markedly stimulated uptake of 125I-labeled b-anti-PECAM in perfused rat lungs and in the lungs of intact animals after either intravenous or intraarterial injection. The antioxidant enzyme catalase conjugated with b-anti-PECAM/SA bound to endothelial cells in culture, entered the cells, escaped intracellular degradation, and protected the cells against H2O2-induced injury. Anti-PECAM/SA/125I-catalase accumulated in the lungs after intravenous injection or in the perfused rat lungs and protected these lungs against H2O2-induced injury. Thus, modification of a poor carrier antibody with biotin and SA provides an approach for facilitation of antibody-mediated drug targeting. Anti-PECAM/SA is a promising candidate for vascular immunotargeting of bioactive drugs.  (+info)

Molecular biology of biotin attachment to proteins. (4/1806)

Enzymatic attachment of biotin to proteins requires the interaction of a distinct domain of the acceptor protein (the "biotin domain") with the enzyme, biotin protein ligase, that catalyzes this essential and rare post-translational modification. Both biotin domains and biotin protein ligases are very strongly conserved throughout biology. This review concerns the protein structures and mechanisms involved in the covalent attachment of biotin to proteins.  (+info)

Human biotinidase isn't just for recycling biotin. (5/1806)

For years, the major role of biotin has been as the coenzyme for four carboxylases in humans. Although there has been evidence that biotin might have other functions, none has been firmly established. The discovery that human serum biotinidase has biotinyl-transferase activity, in addition to biotinidase hydrolase activity, presents new possibilities for the role of biotinidase in biotin metabolism. Specific transfer of biotin to histones by biotinidase provides a possible explanation for why biotin is found in the nucleus and the nature of its role in the regulation of protein transcription. Future studies will help to determine the functions of biotinidase in biotin metabolism and in disease states.  (+info)

Treatment of mouse oocytes with PI-PLC releases 70-kDa (pI 5) and 35- to 45-kDa (pI 5.5) protein clusters from the egg surface and inhibits sperm-oolemma binding and fusion. (6/1806)

The effect of phosphatidyinositol-specific phospholipase C (PI-PLC) on mouse sperm-egg interaction was investigated in this study to determine if glycosyl-phosphatidylinositol (GPI)-anchored proteins are involved in mammalian fertilization. When both sperm and zona-intact oocytes were pretreated with a highly purified preparation of PI-PLC and coincubated, there was no significant effect on sperm-zona pellucida binding; however, fertilization was reduced from 59.6% (control group) to 2.8% (treatment group). A similar reduction in fertilization rates was found when zona-intact oocytes were treated with PI-PLC and washed prior to incubation with untreated sperm. The effect of PI-PLC on sperm binding and fusion with zona-free oocytes was then investigated. Treatment of sperm with PI-PLC had no significant effect on sperm-egg binding or fusion. However, treatment of eggs with PI-PLC significantly reduced sperm-egg binding and fusion from 6.2 bound and 2.1 fused sperm per egg in the control group to 2.1 bound and 0.02 fused sperm per egg in the treatment group. This decrease in sperm-egg binding and fusion depended on the dose of PI-PLC employed, with a maximal inhibitory effect on binding and fusion at 5 and 1 U/ml, respectively. PI-PLC-treated oocytes could be artificially activated by calcium ionophore, demonstrating that the oocytes were functionally viable following treatment. Furthermore, treatment of oocytes with PI-PLC did not reduce the immunoreactivity of the non-GPI-anchored egg surface integrin, alpha6beta1. Taken together, these observations support the hypothesis that PI-PLC affects fertilization by specifically releasing GPI-anchored proteins from the oolemma. In order to identify the oolemmal GPI-anchored proteins involved in fertilization, egg surface proteins were labeled with sulfo-NHS biotin, treated with PI-PLC, and analyzed by two-dimensional gel electrophoresis followed by avidin blotting. A prominent high-molecular-weight protein cluster (approximately 70 kDa, pI 5) and a lower molecular weight (approximately 35-45 kDa, pI 5.5) protein cluster were released from the oolemmal surface as a result of PI-PLC treatment. It is likely that these GPI-anchored egg surface proteins are required for sperm-egg binding and fusion.  (+info)

Critical relationship between glycosylation of recombinant lutropin receptor ectodomain and its secretion from baculovirus-infected insect cells. (7/1806)

The lutropin receptor ectodomain overexpressed under the control of the powerful polyhedrin promoter in baculovirus-infected Sf9 insect cells, is mainly found in an inactive, intracellularly-aggregated form. It is secreted in an active form under the control of the P10 promoter, a somewhat weaker and earlier promoter, at the price of a lower production. The apparent molecular masses of the two species encoded by the same cDNA are 48 kDa and 60-68 kDa, respectively. The relationship between the extent and type of glycosylation and the extracellular targeting for the recombinant lutropin receptor ectodomains was investigated precisely with endoglycosidases, lectins of various specificities, and a glycosylation inhibitor, and tested with monoclonal and polyclonal antibodies. The results indicate that the strong polyhedrin promoter probably overwhelms the processing capacity of the ER in Sf9 cells, so that only a high-mannose precursor is expressed in large amounts. Only a minute amount of protein is secreted, which has been processed by Sf9 exoglycosidases/glycosyltransferases and bears complex/hybrid oligosaccharides. The weaker P10 promoter allows secretion of a mature and active receptor ectodomain, bearing complex glycosylation. An important O-linked glycosylation is also added post-translationally on this species. In particular, beta-galactose and sialic acid residues were specifically detected in the secreted species, evidence of the induction of the corresponding glycosyltransferases or of their genes. These results suggest that Sf9 cells should eventually be engineered with chaperones and glycosyltransferases in order to improve the production of demanding glycoproteins such as the porcine lutropin ectodomain, so as to open the way to resolution of the three-dimensional structures of these receptors.  (+info)

Characterization of the internalization pathways for the cystic fibrosis transmembrane conductance regulator. (8/1806)

Mutations in the gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) chloride channel give rise to the most common lethal genetic disease of Caucasian populations, CF. Although the function of CFTR is primarily related to the regulation of apical membrane chloride permeability, biochemical, immunocytochemical, and functional studies indicate that CFTR is also present in endosomal and trans Golgi compartments. The molecular pathways by which CFTR is internalized into intracellular compartments are not fully understood. To define the pathways for CFTR internalization, we investigated the association of CFTR with two specialized domains of the plasma membrane, clathrin-coated pits and caveolae. Internalization of CFTR was monitored after cell surface biotinylation and quantitation of cell surface CFTR levels after elution of cell lysates from a monomeric avidin column. Cell surface levels of CFTR were determined after disruption of caveolae or clathrin-coated vesicle formation. Biochemical assays revealed that disrupting the formation of clathrin-coated vesicles inhibited the internalization of CFTR from the plasma membrane, resulting in a threefold increase in the steady-state levels of cell surface CFTR. In contrast, the levels of cell surface CFTR after disruption of caveolae were not different from those in control cells. In addition, although our studies show the presence of caveolin at the apical membrane domain of human airway epithelial cells, we were unable to detect CFTR in purified caveolae. These results suggest that CFTR is constitutively internalized from the apical plasma membrane via clathrin-coated pits and that CFTR is excluded from caveolae.  (+info)

Biotinyllation is a process of introducing biotin (a vitamin) into a molecule, such as a protein or nucleic acid (DNA or RNA), through chemical reaction. This modification allows the labeled molecule to be easily detected and isolated using streptavidin-biotin interaction, which has one of the strongest non-covalent bonds in nature. Biotinylated molecules are widely used in various research applications such as protein-protein interaction studies, immunohistochemistry, and blotting techniques.

Biotin is a water-soluble vitamin, also known as Vitamin B7 or Vitamin H. It is a cofactor for several enzymes involved in metabolism, particularly in the synthesis and breakdown of fatty acids, amino acids, and carbohydrates. Biotin plays a crucial role in maintaining healthy skin, hair, nails, nerves, and liver function. It is found in various foods such as nuts, seeds, whole grains, milk, and vegetables. Biotin deficiency is rare but can occur in people with malnutrition, alcoholism, pregnancy, or certain genetic disorders.

Carbon-Nitrogen (C-N) ligases are a class of enzymes that catalyze the joining of a carbon atom from a donor molecule to a nitrogen atom in an acceptor molecule through a process called ligase reaction. This type of enzyme plays a crucial role in various biological processes, including the biosynthesis of amino acids, nucleotides, and other biomolecules that contain both carbon and nitrogen atoms.

C-N ligases typically require ATP or another energy source to drive the reaction forward, as well as cofactors such as metal ions or vitamins to facilitate the chemical bond formation between the carbon and nitrogen atoms. The specificity of C-N ligases varies depending on the enzyme, with some acting only on specific donor and acceptor molecules while others have broader substrate ranges.

Examples of C-N ligases include glutamine synthetase, which catalyzes the formation of glutamine from glutamate and ammonia, and asparagine synthetase, which catalyzes the formation of asparagine from aspartate and ammonia. Understanding the function and regulation of C-N ligases is important for understanding various biological processes and developing strategies to modulate them in disease states.

Biotinidase is an enzyme that is responsible for the release of biotin, a vital nutrient, from proteins in the body. Biotin is essential for various metabolic processes, including the synthesis of fatty acids and glucose. Biotinidase deficiency can lead to serious health problems, such as seizures, developmental delays, and hearing and vision loss. Therefore, biotinidase levels are often measured in newborn screening tests to identify babies who may be at risk for this rare but treatable condition.

Streptavidin is not a medical term per se, but rather a biochemical term used in the field of medicine and laboratory research. Streptavidin is a protein that is derived from the bacterium Streptomyces avidinii. It has a unique ability to bind very strongly and specifically to another molecule called biotin, with an association constant that is one of the strongest non-covalent interactions known in nature.

This property makes streptavidin a valuable tool in various medical and research applications such as immunoassays, histology, molecular biology, and drug delivery systems. For example, biotinylated molecules (such as antibodies, DNA, or enzymes) can be linked to streptavidin for detection, purification, or targeting purposes.

In summary, streptavidin is a bacterial protein that binds strongly and specifically to biotin, which is used in various medical and research applications as a tool for detection, purification, or targeting purposes.

Avidin is a protein found in the white of eggs (egg whites) and some other animal tissues. It has a high binding affinity for biotin, also known as vitamin B7 or vitamin H, which is an essential nutrient for humans and other organisms. This property makes avidin useful in various biochemical and medical applications, such as immunohistochemistry, blotting techniques, and drug delivery systems.

Biotin-avidin interactions are among the strongest non-covalent interactions known in nature, with a dissociation constant (Kd) of approximately 10^-15 M. This means that once biotin is bound to avidin, it is very difficult to separate them. In some cases, this property can be exploited to create stable and specific complexes for various applications.

However, it's worth noting that the high affinity of avidin for biotin can also have negative effects in certain contexts. For example, raw egg whites contain large amounts of avidin, which can bind to biotin in the gut and prevent its absorption if consumed in sufficient quantities. This can lead to biotin deficiency, which can cause various health problems. Cooking egg whites denatures avidin and reduces its ability to bind to biotin, making cooked eggs a safe source of biotin.

Fatty acid synthase type II (FASN2) is an alternative form of fatty acid synthase, which is a multi-functional enzyme complex responsible for the de novo synthesis of palmitate, a 16-carbon saturated fatty acid. In contrast to the classical type I fatty acid synthase (FASN), which is found in the cytoplasm and exists as a homodimer, FASN2 is localized in the mitochondria and consists of individual, monofunctional enzymes that catalyze each step of the fatty acid synthesis process.

The type II fatty acid synthase system includes several enzymes: acetyl-CoA carboxylase (ACC), which provides malonyl-CoA; 3-ketoacyl-CoA thiolase, which catalyzes the initial condensation of acetyl-CoA and malonyl-CoA to form acetoacetyl-CoA; 3-hydroxyacyl-CoA dehydrogenase/enoyl-CoA hydratase (HAD), which catalyzes the reduction, dehydration, and isomerization of acetoacetyl-CoA to form hydroxybutyryl-CoA; 3-ketoacyl-CoA reductase, which reduces hydroxybutyryl-CoA to butyryl-CoA; and enoyl-CoA reductase (ECR), which catalyzes the final reduction of butyryl-CoA to palmitate.

FASN2 is involved in various cellular processes, including energy metabolism, lipid biosynthesis, and protein acetylation. Dysregulation of FASN2 has been implicated in several diseases, such as cancer, obesity, and neurodegenerative disorders.

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.

Methylmalonyl-CoA decarboxylase is a mitochondrial enzyme that plays a crucial role in the metabolism of certain amino acids and fatty acids. Specifically, it catalyzes the conversion of methylmalonyl-CoA to propionyl-CoA through the decarboxylation of the thioester bond.

The reaction is as follows:

Methylmalonyl-CoA → Propionyl-CoA + CO2

This enzyme requires biotin as a cofactor, and its activity is reduced in individuals with methylmalonic acidemia, a rare inherited metabolic disorder caused by mutations in the MMAB or MCEE genes that encode subunits of the methylmalonyl-CoA decarboxylase enzyme complex.

Deficiency of this enzyme leads to an accumulation of methylmalonic acid and methylmalonyl-CoA, which can cause metabolic acidosis, hyperammonemia, and other symptoms associated with the disorder.

Holocarboxylase Synthetase Deficiency (HCD) is a rare genetic disorder of biotin metabolism, characterized by the body's inability to properly utilize the vitamin biotin. Biotin plays a crucial role in various essential functions, such as the breakdown of fats, proteins, and carbohydrates, as well as the regulation of gene expression.

Holocarboxylase synthetase is an enzyme responsible for attaching biotin to four different carboxylases, which are necessary for these vital processes. In Holocarboxylase Synthetase Deficiency, this enzyme is either partially or completely nonfunctional due to mutations in the HLCS gene.

The symptoms of HCD can vary widely but often include:

1. Feeding difficulties and poor growth in infancy
2. Severe metabolic acidosis
3. Ketoacidosis
4. Delayed development
5. Hypotonia (low muscle tone)
6. Skin rashes
7. Hair loss
8. Neurological symptoms, such as seizures and ataxia (loss of coordination and balance)

If left untreated, Holocarboxylase Synthetase Deficiency can lead to severe complications, including developmental delays, neurological damage, and even death. However, with early diagnosis and proper treatment involving biotin supplementation, many of these symptoms can be managed, and the progression of the disorder can be slowed or stopped.

Protein transport, in the context of cellular biology, refers to the process by which proteins are actively moved from one location to another within or between cells. This is a crucial mechanism for maintaining proper cell function and regulation.

Intracellular protein transport involves the movement of proteins within a single cell. Proteins can be transported across membranes (such as the nuclear envelope, endoplasmic reticulum, Golgi apparatus, or plasma membrane) via specialized transport systems like vesicles and transport channels.

Intercellular protein transport refers to the movement of proteins from one cell to another, often facilitated by exocytosis (release of proteins in vesicles) and endocytosis (uptake of extracellular substances via membrane-bound vesicles). This is essential for communication between cells, immune response, and other physiological processes.

It's important to note that any disruption in protein transport can lead to various diseases, including neurological disorders, cancer, and metabolic conditions.

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.

Carboxyl transferases and carbamoyl transferases are two types of enzymes that play a crucial role in various metabolic pathways by transferring a carboxyl or carbamoyl group from one molecule to another. Here are the medical definitions for both:

1. Carboxyl Transferases: These are a class of enzymes that catalyze the transfer of a carboxyl group (-COOH) from one molecule to another. They play an essential role in several metabolic processes, such as the synthesis and degradation of amino acids, carbohydrates, lipids, and other biomolecules. One example of a carboxyl transferase is pyruvate carboxylase, which catalyzes the addition of a carboxyl group to pyruvate, forming oxaloacetate in the gluconeogenesis pathway.
2. Carbamoyl Transferases: These are enzymes that facilitate the transfer of a carbamoyl group (-CONH2) from one molecule to another. They participate in various metabolic reactions, including the synthesis of essential compounds like arginine, pyrimidines, and urea. An example of a carbamoyl transferase is ornithine carbamoyltransferase (OCT), which catalyzes the transfer of a carbamoyl group from carbamoyl phosphate to ornithine during the urea cycle.

Both carboxyl and carbamoyl transferases are vital for maintaining proper cellular function and homeostasis in living organisms, including humans. Dysregulation or deficiency of these enzymes can lead to various metabolic disorders and diseases.

Carbon-carbon ligases are a type of enzyme that catalyze the formation of carbon-carbon bonds between two molecules. These enzymes play important roles in various biological processes, including the biosynthesis of natural products and the metabolism of carbohydrates and lipids.

Carbon-carbon ligases can be classified into several categories based on the type of reaction they catalyze. For example, aldolases catalyze the condensation of an aldehyde or ketone with another molecule to form a new carbon-carbon bond and a new carbonyl group. Other examples include the polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs), which are large multienzyme complexes that catalyze the sequential addition of activated carbon units to form complex natural products.

Carbon-carbon ligases are important targets for drug discovery and development, as they play critical roles in the biosynthesis of many disease-relevant molecules. Inhibitors of these enzymes have shown promise as potential therapeutic agents for a variety of diseases, including cancer, infectious diseases, and metabolic disorders.

Acetyl-CoA carboxylase (ACCA) is a biotin-dependent enzyme that plays a crucial role in fatty acid synthesis. It catalyzes the conversion of acetyl-CoA to malonyl-CoA, which is the first and rate-limiting step in the synthesis of long-chain fatty acids. The reaction catalyzed by ACCA is as follows:

acetyl-CoA + HCO3- + ATP + 2H+ --> malonyl-CoA + CoA + ADP + Pi + 2H2O

ACCA exists in two isoforms, a cytosolic form (ACC1) and a mitochondrial form (ACC2). ACC1 is primarily involved in fatty acid synthesis, while ACC2 is responsible for the regulation of fatty acid oxidation. The activity of ACCA is regulated by several factors, including phosphorylation/dephosphorylation, allosteric regulation, and transcriptional regulation. Dysregulation of ACCA has been implicated in various metabolic disorders, such as obesity, insulin resistance, and non-alcoholic fatty liver disease.

Epigenetic repression refers to the process by which gene expression is suppressed or silenced through epigenetic modifications. These modifications include DNA methylation, histone modification, and non-coding RNA regulation, among others.

In particular, DNA methylation involves the addition of a methyl group (-CH3) to the cytosine residue in a CpG dinucleotide, which typically results in the recruitment of proteins that compact chromatin and prevent transcription factors from accessing the promoter region of the gene.

Histone modification involves the addition or removal of chemical groups such as methyl, acetyl, or ubiquitin to histone proteins around which DNA is wrapped, leading to changes in chromatin structure and gene expression.

Non-coding RNA regulation includes the action of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), which can bind to messenger RNAs (mRNAs) and prevent their translation into proteins, thereby repressing gene expression.

Overall, epigenetic repression plays a crucial role in regulating gene expression during development, differentiation, and disease states such as cancer.

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.

Multiple carboxylase deficiency (MCD) is a rare genetic disorder that affects the body's ability to metabolize certain amino acids, particularly those that contain sulfur. It is caused by mutations in the genes responsible for producing enzymes involved in the biotin-dependent carboxylation reactions, which are critical for various metabolic processes in the body.

There are two major types of MCD:

1. Profound multiple carboxylase deficiency (also known as Type II biotinidase deficiency): This form is more severe and is caused by a defect in the holocarboxylase synthetase enzyme, which is responsible for attaching biotin to several carboxylases.
2. Biotin-responsive multiple carboxylase deficiency (also known as Type I biotinidase deficiency): This form is milder and is caused by a defect in the biotinidase enzyme, which recycles biotin in the body. However, it can be treated with biotin supplementation.

Symptoms of MCD may include:

* Developmental delay
* Seizures
* Hypotonia (low muscle tone)
* Ataxia (lack of coordination)
* Rash
* Hair loss
* Acidosis (high levels of acid in the body)
* Coma and even death, if left untreated

Early diagnosis and treatment with biotin supplementation can significantly improve outcomes for individuals with MCD.

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.

Carbonic anhydrase I is a specific type of carbonic anhydrase, which is an enzyme that catalyzes the reversible reaction between carbon dioxide and water to form carbonic acid. This enzyme is primarily found in red blood cells and plays a crucial role in maintaining pH balance and regulating respiration.

Carbonic anhydrase I, also known as CA I or CA-I, is responsible for hydrating carbon dioxide to form bicarbonate ions and protons, which helps maintain the acid-base balance in the body. It has a relatively slower reaction rate compared to other carbonic anhydrase isoforms.

Defects or mutations in the CA I gene can lead to reduced enzymatic activity and may contribute to certain medical conditions, such as distal renal tubular acidosis (dRTA), a disorder characterized by impaired kidney function and acid-base imbalances. However, other carbonic anhydrase isoforms can compensate for the loss of CA I activity in most cases, so its deficiency rarely causes severe symptoms on its own.

Endocytosis is the process by which cells absorb substances from their external environment by engulfing them in membrane-bound structures, resulting in the formation of intracellular vesicles. This mechanism allows cells to take up large molecules, such as proteins and lipids, as well as small particles, like bacteria and viruses. There are two main types of endocytosis: phagocytosis (cell eating) and pinocytosis (cell drinking). Phagocytosis involves the engulfment of solid particles, while pinocytosis deals with the uptake of fluids and dissolved substances. Other specialized forms of endocytosis include receptor-mediated endocytosis and caveolae-mediated endocytosis, which allow for the specific internalization of molecules through the interaction with cell surface receptors.

Lysine is an essential amino acid, which means that it cannot be synthesized by the human body and must be obtained through the diet. Its chemical formula is (2S)-2,6-diaminohexanoic acid. Lysine is necessary for the growth and maintenance of tissues in the body, and it plays a crucial role in the production of enzymes, hormones, and antibodies. It is also essential for the absorption of calcium and the formation of collagen, which is an important component of bones and connective tissue. Foods that are good sources of lysine include meat, poultry, fish, eggs, and dairy products.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Histones are highly alkaline proteins found in the chromatin of eukaryotic cells. They are rich in basic amino acid residues, such as arginine and lysine, which give them their positive charge. Histones play a crucial role in packaging DNA into a more compact structure within the nucleus by forming a complex with it called a nucleosome. Each nucleosome contains about 146 base pairs of DNA wrapped around an octamer of eight histone proteins (two each of H2A, H2B, H3, and H4). The N-terminal tails of these histones are subject to various post-translational modifications, such as methylation, acetylation, and phosphorylation, which can influence chromatin structure and gene expression. Histone variants also exist, which can contribute to the regulation of specific genes and other nuclear processes.

Succinimides are a group of anticonvulsant medications used to treat various types of seizures. They include drugs such as ethosuximide, methsuximide, and phensuximide. These medications work by reducing the abnormal electrical activity in the brain that leads to seizures.

The name "succinimides" comes from their chemical structure, which contains a five-membered ring containing two nitrogen atoms and a carbonyl group. This structure is similar to that of other anticonvulsant medications, such as barbiturates, but the succinimides have fewer side effects and are less likely to cause sedation or respiratory depression.

Succinimides are primarily used to treat absence seizures, which are characterized by brief periods of staring and lack of responsiveness. They may also be used as adjunctive therapy in the treatment of generalized tonic-clonic seizures and other types of seizures.

Like all medications, succinimides can cause side effects, including nausea, vomiting, dizziness, headache, and rash. More serious side effects, such as blood dyscrasias, liver toxicity, and Stevens-Johnson syndrome, are rare but have been reported. It is important for patients taking succinimides to be monitored regularly by their healthcare provider to ensure safe and effective use of the medication.

Pyruvate carboxylase is a biotin-containing enzyme that plays a crucial role in gluconeogenesis, the process of generating new glucose molecules from non-carbohydrate sources. The enzyme catalyzes the conversion of pyruvate to oxaloacetate, an important intermediate in several metabolic pathways, particularly in the liver, kidneys, and brain.

The reaction catalyzed by pyruvate carboxylase is as follows:

Pyruvate + CO2 + ATP + H2O → Oxaloacetate + ADP + Pi + 2H+

In this reaction, pyruvate reacts with bicarbonate (HCO3-) to form oxaloacetate, consuming one molecule of ATP in the process. The generation of oxaloacetate provides a key entry point for non-carbohydrate precursors, such as lactate and certain amino acids, to enter the gluconeogenic pathway.

Pyruvate carboxylase deficiency is a rare but severe genetic disorder that can lead to neurological impairment and developmental delays due to the disruption of energy metabolism in the brain.

A symporter is a type of transmembrane protein that functions to transport two or more molecules or ions across a biological membrane in the same direction, simultaneously. This process is called co-transport and it is driven by the concentration gradient of one of the substrates, which is usually an ion such as sodium (Na+) or proton (H+).

Symporters are classified based on the type of energy that drives the transport process. Primary active transporters, such as symporters, use the energy from ATP hydrolysis or from the electrochemical gradient of ions to move substrates against their concentration gradient. In contrast, secondary active transporters use the energy stored in an existing electrochemical gradient of one substrate to drive the transport of another substrate against its own concentration gradient.

Symporters play important roles in various physiological processes, including nutrient uptake, neurotransmitter reuptake, and ion homeostasis. For example, the sodium-glucose transporter (SGLT) is a symporter that co-transports glucose and sodium ions across the intestinal epithelium and the renal proximal tubule, contributing to glucose absorption and regulation of blood glucose levels. Similarly, the dopamine transporter (DAT) is a symporter that co-transports dopamine and sodium ions back into presynaptic neurons, terminating the action of dopamine in the synapse.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

'Escherichia coli (E. coli) proteins' refer to the various types of proteins that are produced and expressed by the bacterium Escherichia coli. These proteins play a critical role in the growth, development, and survival of the organism. They are involved in various cellular processes such as metabolism, DNA replication, transcription, translation, repair, and regulation.

E. coli is a gram-negative, facultative anaerobe that is commonly found in the intestines of warm-blooded organisms. It is widely used as a model organism in scientific research due to its well-studied genetics, rapid growth, and ability to be easily manipulated in the laboratory. As a result, many E. coli proteins have been identified, characterized, and studied in great detail.

Some examples of E. coli proteins include enzymes involved in carbohydrate metabolism such as lactase, sucrase, and maltose; proteins involved in DNA replication such as the polymerases, single-stranded binding proteins, and helicases; proteins involved in transcription such as RNA polymerase and sigma factors; proteins involved in translation such as ribosomal proteins, tRNAs, and aminoacyl-tRNA synthetases; and regulatory proteins such as global regulators, two-component systems, and transcription factors.

Understanding the structure, function, and regulation of E. coli proteins is essential for understanding the basic biology of this important organism, as well as for developing new strategies for combating bacterial infections and improving industrial processes involving bacteria.

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.

Biological transport refers to the movement of molecules, ions, or solutes across biological membranes or through cells in living organisms. This process is essential for maintaining homeostasis, regulating cellular functions, and enabling communication between cells. There are two main types of biological transport: passive transport and active transport.

Passive transport does not require the input of energy and includes:

1. Diffusion: The random movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
3. Facilitated diffusion: The assisted passage of polar or charged substances through protein channels or carriers in the cell membrane, which increases the rate of diffusion without consuming energy.

Active transport requires the input of energy (in the form of ATP) and includes:

1. Primary active transport: The direct use of ATP to move molecules against their concentration gradient, often driven by specific transport proteins called pumps.
2. Secondary active transport: The coupling of the movement of one substance down its electrochemical gradient with the uphill transport of another substance, mediated by a shared transport protein. This process is also known as co-transport or counter-transport.

HEK293 cells, also known as human embryonic kidney 293 cells, are a line of cells used in scientific research. They were originally derived from human embryonic kidney cells and have been adapted to grow in a lab setting. HEK293 cells are widely used in molecular biology and biochemistry because they can be easily transfected (a process by which DNA is introduced into cells) and highly express foreign genes. As a result, they are often used to produce proteins for structural and functional studies. It's important to note that while HEK293 cells are derived from human tissue, they have been grown in the lab for many generations and do not retain the characteristics of the original embryonic kidney cells.

Repressor proteins are a type of regulatory protein in molecular biology that suppress the transcription of specific genes into messenger RNA (mRNA) by binding to DNA. They function as part of gene regulation processes, often working in conjunction with an operator region and a promoter region within the DNA molecule. Repressor proteins can be activated or deactivated by various signals, allowing for precise control over gene expression in response to changing cellular conditions.

There are two main types of repressor proteins:

1. DNA-binding repressors: These directly bind to specific DNA sequences (operator regions) near the target gene and prevent RNA polymerase from transcribing the gene into mRNA.
2. Allosteric repressors: These bind to effector molecules, which then cause a conformational change in the repressor protein, enabling it to bind to DNA and inhibit transcription.

Repressor proteins play crucial roles in various biological processes, such as development, metabolism, and stress response, by controlling gene expression patterns in cells.

Cell polarity refers to the asymmetric distribution of membrane components, cytoskeleton, and organelles in a cell. This asymmetry is crucial for various cellular functions such as directed transport, cell division, and signal transduction. The plasma membrane of polarized cells exhibits distinct domains with unique protein and lipid compositions that define apical, basal, and lateral surfaces of the cell.

In epithelial cells, for example, the apical surface faces the lumen or external environment, while the basolateral surface interacts with other cells or the extracellular matrix. The establishment and maintenance of cell polarity are regulated by various factors including protein complexes, lipids, and small GTPases. Loss of cell polarity has been implicated in several diseases, including cancer and neurological disorders.

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.

Glycosylation is the enzymatic process of adding a sugar group, or glycan, to a protein, lipid, or other organic molecule. This post-translational modification plays a crucial role in modulating various biological functions, such as protein stability, trafficking, and ligand binding. The structure and composition of the attached glycans can significantly influence the functional properties of the modified molecule, contributing to cell-cell recognition, signal transduction, and immune response regulation. Abnormal glycosylation patterns have been implicated in several disease states, including cancer, diabetes, and neurodegenerative disorders.

Post-translational protein processing refers to the modifications and changes that proteins undergo after their synthesis on ribosomes, which are complex molecular machines responsible for protein synthesis. These modifications occur through various biochemical processes and play a crucial role in determining the final structure, function, and stability of the protein.

The process begins with the translation of messenger RNA (mRNA) into a linear polypeptide chain, which is then subjected to several post-translational modifications. These modifications can include:

1. Proteolytic cleavage: The removal of specific segments or domains from the polypeptide chain by proteases, resulting in the formation of mature, functional protein subunits.
2. Chemical modifications: Addition or modification of chemical groups to the side chains of amino acids, such as phosphorylation (addition of a phosphate group), glycosylation (addition of sugar moieties), methylation (addition of a methyl group), acetylation (addition of an acetyl group), and ubiquitination (addition of a ubiquitin protein).
3. Disulfide bond formation: The oxidation of specific cysteine residues within the polypeptide chain, leading to the formation of disulfide bonds between them. This process helps stabilize the three-dimensional structure of proteins, particularly in extracellular environments.
4. Folding and assembly: The acquisition of a specific three-dimensional conformation by the polypeptide chain, which is essential for its function. Chaperone proteins assist in this process to ensure proper folding and prevent aggregation.
5. Protein targeting: The directed transport of proteins to their appropriate cellular locations, such as the nucleus, mitochondria, endoplasmic reticulum, or plasma membrane. This is often facilitated by specific signal sequences within the protein that are recognized and bound by transport machinery.

Collectively, these post-translational modifications contribute to the functional diversity of proteins in living organisms, allowing them to perform a wide range of cellular processes, including signaling, catalysis, regulation, and structural support.

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.

Confocal microscopy is a powerful imaging technique used in medical and biological research to obtain high-resolution, contrast-rich images of thick samples. This super-resolution technology provides detailed visualization of cellular structures and processes at various depths within a specimen.

In confocal microscopy, a laser beam focused through a pinhole illuminates a small spot within the sample. The emitted fluorescence or reflected light from this spot is then collected by a detector, passing through a second pinhole that ensures only light from the focal plane reaches the detector. This process eliminates out-of-focus light, resulting in sharp images with improved contrast compared to conventional widefield microscopy.

By scanning the laser beam across the sample in a raster pattern and collecting fluorescence at each point, confocal microscopy generates optical sections of the specimen. These sections can be combined to create three-dimensional reconstructions, allowing researchers to study cellular architecture and interactions within complex tissues.

Confocal microscopy has numerous applications in medical research, including studying protein localization, tracking intracellular dynamics, analyzing cell morphology, and investigating disease mechanisms at the cellular level. Additionally, it is widely used in clinical settings for diagnostic purposes, such as analyzing skin lesions or detecting pathogens in patient samples.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

"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.

Immunoprecipitation (IP) is a research technique used in molecular biology and immunology to isolate specific antigens or antibodies from a mixture. It involves the use of an antibody that recognizes and binds to a specific antigen, which is then precipitated out of solution using various methods, such as centrifugation or chemical cross-linking.

In this technique, an antibody is first incubated with a sample containing the antigen of interest. The antibody specifically binds to the antigen, forming an immune complex. This complex can then be captured by adding protein A or G agarose beads, which bind to the constant region of the antibody. The beads are then washed to remove any unbound proteins, leaving behind the precipitated antigen-antibody complex.

Immunoprecipitation is a powerful tool for studying protein-protein interactions, post-translational modifications, and signal transduction pathways. It can also be used to detect and quantify specific proteins in biological samples, such as cells or tissues, and to identify potential biomarkers of disease.

'Staining and labeling' are techniques commonly used in pathology, histology, cytology, and molecular biology to highlight or identify specific components or structures within tissues, cells, or molecules. These methods enable researchers and medical professionals to visualize and analyze the distribution, localization, and interaction of biological entities, contributing to a better understanding of diseases, cellular processes, and potential therapeutic targets.

Medical definitions for 'staining' and 'labeling' are as follows:

1. Staining: A process that involves applying dyes or stains to tissues, cells, or molecules to enhance their contrast and reveal specific structures or components. Stains can be categorized into basic stains (which highlight acidic structures) and acidic stains (which highlight basic structures). Common staining techniques include Hematoxylin and Eosin (H&E), which differentiates cell nuclei from the surrounding cytoplasm and extracellular matrix; special stains, such as PAS (Periodic Acid-Schiff) for carbohydrates or Masson's trichrome for collagen fibers; and immunostains, which use antibodies to target specific proteins.
2. Labeling: A process that involves attaching a detectable marker or tag to a molecule of interest, allowing its identification, quantification, or tracking within a biological system. Labels can be direct, where the marker is directly conjugated to the targeting molecule, or indirect, where an intermediate linker molecule is used to attach the label to the target. Common labeling techniques include fluorescent labels (such as FITC, TRITC, or Alexa Fluor), enzymatic labels (such as horseradish peroxidase or alkaline phosphatase), and radioactive labels (such as ³²P or ¹⁴C). Labeling is often used in conjunction with staining techniques to enhance the specificity and sensitivity of detection.

Together, staining and labeling provide valuable tools for medical research, diagnostics, and therapeutic development, offering insights into cellular and molecular processes that underlie health and disease.

I apologize for any confusion, but "Pyrococcus horikoshii" is not a medical term or concept. It is actually the name of a species of archaea, which are single-celled microorganisms that share some characteristics with both bacteria and eukaryotes (complex cells like those found in animals, plants, and fungi).

"Pyrococcus horikoshii" is particularly notable for its ability to thrive in extremely high temperature environments, with an optimum growth temperature of around 100 degrees Celsius. It was first isolated from a marine volcanic hot spring near Kuroshio, Japan. This organism has been studied extensively in the field of molecular biology and genetics due to its unique properties and potential applications in biotechnology.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Glutamate plasma membrane transport proteins, also known as excitatory amino acid transporters (EAATs), are a type of membrane protein responsible for the uptake of glutamate from the extracellular space into neurons and glial cells in the central nervous system. These transporters play a crucial role in maintaining appropriate levels of glutamate, an important neurotransmitter, in the synaptic cleft to prevent excitotoxicity and ensure normal neurotransmission. There are five subtypes of EAATs (EAAT1-EAAT5) identified in mammals, each with distinct expression patterns and functions.

Collecting kidney tubules, also known as collecting ducts, are the final portion of the renal tubule in the nephron of the kidney. They collect filtrate from the distal convoluted tubules and glomeruli and are responsible for the reabsorption of water and electrolytes back into the bloodstream under the influence of antidiuretic hormone (ADH) and aldosterone. The collecting ducts then deliver the remaining filtrate to the ureter, which transports it to the bladder for storage until urination.

CHO cells, or Chinese Hamster Ovary cells, are a type of immortalized cell line that are commonly used in scientific research and biotechnology. They were originally derived from the ovaries of a female Chinese hamster (Cricetulus griseus) in the 1950s.

CHO cells have several characteristics that make them useful for laboratory experiments. They can grow and divide indefinitely under appropriate conditions, which allows researchers to culture large quantities of them for study. Additionally, CHO cells are capable of expressing high levels of recombinant proteins, making them a popular choice for the production of therapeutic drugs, vaccines, and other biologics.

In particular, CHO cells have become a workhorse in the field of biotherapeutics, with many approved monoclonal antibody-based therapies being produced using these cells. The ability to genetically modify CHO cells through various methods has further expanded their utility in research and industrial applications.

It is important to note that while CHO cells are widely used in scientific research, they may not always accurately represent human cell behavior or respond to drugs and other compounds in the same way as human cells do. Therefore, results obtained using CHO cells should be validated in more relevant systems when possible.

Membrane transport proteins are specialized biological molecules, specifically integral membrane proteins, that facilitate the movement of various substances across the lipid bilayer of cell membranes. They are responsible for the selective and regulated transport of ions, sugars, amino acids, nucleotides, and other molecules into and out of cells, as well as within different cellular compartments. These proteins can be categorized into two main types: channels and carriers (or pumps). Channels provide a passive transport mechanism, allowing ions or small molecules to move down their electrochemical gradient, while carriers actively transport substances against their concentration gradient, requiring energy usually in the form of ATP. Membrane transport proteins play a crucial role in maintaining cell homeostasis, signaling processes, and many other physiological functions.

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

Solute Carrier Family 12, Member 1 (SLC12A1) is a protein that functions as a sodium-potassium-chloride cotransporter (NKCC1). It is responsible for the transport of sodium, potassium, and chloride ions across the membrane of cells. This transporter plays a crucial role in regulating the volume and composition of fluids in various tissues, including the inner ear and brain. Dysfunction of this protein has been implicated in several medical conditions, such as hearing loss, balance disorders, and neurological disorders.

Epithelial Sodium Channels (ENaC) are a type of ion channel found in the epithelial cells that line the surface of many types of tissues, including the airways, kidneys, and colon. These channels play a crucial role in regulating sodium and fluid balance in the body by allowing the passive movement of sodium ions (Na+) from the lumen or outside of the cell to the inside of the cell, following their electrochemical gradient.

ENaC is composed of three subunits, alpha, beta, and gamma, which are encoded by different genes. The channel is normally closed and opens in response to various stimuli, such as hormones, neurotransmitters, or changes in osmolarity. Once open, the channel allows sodium ions to flow through, creating a positive charge that can attract chloride ions (Cl-) and water molecules, leading to fluid absorption.

In the kidneys, ENaC plays an essential role in regulating sodium reabsorption in the distal nephron, which helps maintain blood pressure and volume. In the airways, ENaC is involved in controlling the hydration of the airway surface liquid, which is necessary for normal mucociliary clearance. Dysregulation of ENaC has been implicated in several diseases, including hypertension, cystic fibrosis, and chronic obstructive pulmonary disease (COPD).

Propionibacterium is a genus of gram-positive, rod-shaped bacteria that are commonly found on the skin and in the mouth, intestines, and genitourinary tract of humans and animals. They are named after their ability to produce propionic acid as a major metabolic end product. Some species of Propionibacterium, such as P. acnes, are associated with skin conditions like acne vulgaris, where they contribute to the inflammatory response that leads to the formation of pimples and lesions. Other species, such as P. freudenreichii, are used in the food industry for the production of dairy products like Swiss cheese and yogurt. Propionibacterium species are generally considered to be non-pathogenic or opportunistic pathogens, meaning that they can cause infection under certain circumstances, such as when the immune system is compromised.

"Magnetospirillum" is a genus of bacteria that are capable of magnetotaxis, which means they can align and move along the magnetic field lines of the Earth. They possess unique structures called magnetosomes, which are membrane-enclosed magnetic nanocrystals. These nanocrystals act as intracellular compasses, helping the bacteria navigate through their environment. The genus Magnetospirillum includes several species, such as Magnetospirillum magneticum and Magnetospirillum gryphiswaldense, which are commonly used in research to study bacterial magnetotaxis, biomineralization, and other microbiological processes.

'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.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

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.

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.

Epithelial cells are types of cells that cover the outer surfaces of the body, line the inner surfaces of organs and glands, and form the lining of blood vessels and body cavities. They provide a protective barrier against the external environment, regulate the movement of materials between the internal and external environments, and are involved in the sense of touch, temperature, and pain. Epithelial cells can be squamous (flat and thin), cuboidal (square-shaped and of equal height), or columnar (tall and narrow) in shape and are classified based on their location and function.

Carboxy-lyases are a class of enzymes that catalyze the removal of a carboxyl group from a substrate, often releasing carbon dioxide in the process. These enzymes play important roles in various metabolic pathways, such as the biosynthesis and degradation of amino acids, sugars, and other organic compounds.

Carboxy-lyases are classified under EC number 4.2 in the Enzyme Commission (EC) system. They can be further divided into several subclasses based on their specific mechanisms and substrates. For example, some carboxy-lyases require a cofactor such as biotin or thiamine pyrophosphate to facilitate the decarboxylation reaction, while others do not.

Examples of carboxy-lyases include:

1. Pyruvate decarboxylase: This enzyme catalyzes the conversion of pyruvate to acetaldehyde and carbon dioxide during fermentation in yeast and other organisms.
2. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO): This enzyme is essential for photosynthesis in plants and some bacteria, as it catalyzes the fixation of carbon dioxide into an organic molecule during the Calvin cycle.
3. Phosphoenolpyruvate carboxylase: Found in plants, algae, and some bacteria, this enzyme plays a role in anaplerotic reactions that replenish intermediates in the citric acid cycle. It catalyzes the conversion of phosphoenolpyruvate to oxaloacetate and inorganic phosphate.
4. Aspartate transcarbamylase: This enzyme is involved in the biosynthesis of pyrimidines, a class of nucleotides. It catalyzes the transfer of a carboxyl group from carbamoyl aspartate to carbamoyl phosphate, forming cytidine triphosphate (CTP) and fumarate.
5. Urocanase: Found in animals, this enzyme is involved in histidine catabolism. It catalyzes the conversion of urocanate to formiminoglutamate and ammonia.

Jurkat cells are a type of human immortalized T lymphocyte (a type of white blood cell) cell line that is commonly used in scientific research. They were originally isolated from the peripheral blood of a patient with acute T-cell leukemia. Jurkat cells are widely used as a model system to study T-cell activation, signal transduction, and apoptosis (programmed cell death). They are also used in the study of HIV infection and replication, as they can be infected with the virus and used to investigate viral replication and host cell responses.

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.

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a protein that functions as a chloride channel in the membranes of various cells, including those in the lungs and pancreas. Mutations in the gene encoding CFTR can lead to Cystic Fibrosis, a genetic disorder characterized by thick, sticky mucus in the lungs and other organs, leading to severe respiratory and digestive problems.

CFTR is normally activated by cyclic AMP-dependent protein kinase (PKA) and regulates the movement of chloride ions across cell membranes. In Cystic Fibrosis, mutations in CFTR can result in impaired channel function or reduced amounts of functional CFTR at the cell surface, leading to an imbalance in ion transport and fluid homeostasis. This can cause the production of thick, sticky mucus that clogs the airways and leads to chronic lung infections, as well as other symptoms associated with Cystic Fibrosis.

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.

I'm sorry for any confusion, but "opossums" are not a medical term or a medical condition. Opossums are actually marsupials (pouched mammals) that are native to the Americas. They are often known for their "playing dead" behavior as a defense mechanism when threatened. If you have any questions about medical terminology or health-related topics, I'd be happy to help with those!

Dopamine plasma membrane transport proteins, also known as dopamine transporters (DAT), are a type of protein found in the cell membrane that play a crucial role in the regulation of dopamine neurotransmission. They are responsible for the reuptake of dopamine from the synaptic cleft back into the presynaptic neuron, thereby terminating the signal transduction of dopamine and regulating the amount of dopamine available for further release.

Dopamine transporters belong to the family of sodium-dependent neurotransmitter transporters and are encoded by the SLC6A3 gene in humans. Abnormalities in dopamine transporter function have been implicated in several neurological and psychiatric disorders, including Parkinson's disease, attention deficit hyperactivity disorder (ADHD), and substance use disorders.

In summary, dopamine plasma membrane transport proteins are essential for the regulation of dopamine neurotransmission by mediating the reuptake of dopamine from the synaptic cleft back into the presynaptic neuron.

A kidney, in medical terms, is one of two bean-shaped organs located in the lower back region of the body. They are essential for maintaining homeostasis within the body by performing several crucial functions such as:

1. Regulation of water and electrolyte balance: Kidneys help regulate the amount of water and various electrolytes like sodium, potassium, and calcium in the bloodstream to maintain a stable internal environment.

2. Excretion of waste products: They filter waste products from the blood, including urea (a byproduct of protein metabolism), creatinine (a breakdown product of muscle tissue), and other harmful substances that result from normal cellular functions or external sources like medications and toxins.

3. Endocrine function: Kidneys produce several hormones with important roles in the body, such as erythropoietin (stimulates red blood cell production), renin (regulates blood pressure), and calcitriol (activated form of vitamin D that helps regulate calcium homeostasis).

4. pH balance regulation: Kidneys maintain the proper acid-base balance in the body by excreting either hydrogen ions or bicarbonate ions, depending on whether the blood is too acidic or too alkaline.

5. Blood pressure control: The kidneys play a significant role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS), which constricts blood vessels and promotes sodium and water retention to increase blood volume and, consequently, blood pressure.

Anatomically, each kidney is approximately 10-12 cm long, 5-7 cm wide, and 3 cm thick, with a weight of about 120-170 grams. They are surrounded by a protective layer of fat and connected to the urinary system through the renal pelvis, ureters, bladder, and urethra.

Caco-2 cells are a type of human epithelial colorectal adenocarcinoma cell line that is commonly used in scientific research, particularly in the field of drug development and toxicology. These cells are capable of forming a monolayer with tight junctions, which makes them an excellent model for studying intestinal absorption, transport, and metabolism of drugs and other xenobiotic compounds.

Caco-2 cells express many of the transporters and enzymes that are found in the human small intestine, making them a valuable tool for predicting drug absorption and bioavailability in humans. They are also used to study the mechanisms of drug transport across the intestinal epithelium, including passive diffusion and active transport by various transporters.

In addition to their use in drug development, Caco-2 cells are also used to study the toxicological effects of various compounds on human intestinal cells. They can be used to investigate the mechanisms of toxicity, as well as to evaluate the potential for drugs and other compounds to induce intestinal damage or inflammation.

Overall, Caco-2 cells are a widely used and valuable tool in both drug development and toxicology research, providing important insights into the absorption, transport, metabolism, and toxicity of various compounds in the human body.

Brefeldin A is a fungal metabolite that inhibits protein transport from the endoplasmic reticulum to the Golgi apparatus. It disrupts the organization of the Golgi complex and causes the redistribution of its proteins to the endoplasmic reticulum. Brefeldin A is used in research to study various cellular processes, including vesicular transport, protein trafficking, and signal transduction pathways. In medicine, it has been studied as a potential anticancer agent due to its ability to induce apoptosis (programmed cell death) in certain types of cancer cells. However, its clinical use is not yet approved.

Immunoblotting, also known as western blotting, is a laboratory technique used in molecular biology and immunogenetics to detect and quantify specific proteins in a complex mixture. This technique combines the electrophoretic separation of proteins by gel electrophoresis with their detection using antibodies that recognize specific epitopes (protein fragments) on the target protein.

The process involves several steps: first, the protein sample is separated based on size through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Next, the separated proteins are transferred onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric field. The membrane is then blocked with a blocking agent to prevent non-specific binding of antibodies.

After blocking, the membrane is incubated with a primary antibody that specifically recognizes the target protein. Following this, the membrane is washed to remove unbound primary antibodies and then incubated with a secondary antibody conjugated to an enzyme such as horseradish peroxidase (HRP) or alkaline phosphatase (AP). The enzyme catalyzes a colorimetric or chemiluminescent reaction that allows for the detection of the target protein.

Immunoblotting is widely used in research and clinical settings to study protein expression, post-translational modifications, protein-protein interactions, and disease biomarkers. It provides high specificity and sensitivity, making it a valuable tool for identifying and quantifying proteins in various biological samples.

Affinity chromatography is a type of chromatography technique used in biochemistry and molecular biology to separate and purify proteins based on their biological characteristics, such as their ability to bind specifically to certain ligands or molecules. This method utilizes a stationary phase that is coated with a specific ligand (e.g., an antibody, antigen, receptor, or enzyme) that selectively interacts with the target protein in a sample.

The process typically involves the following steps:

1. Preparation of the affinity chromatography column: The stationary phase, usually a solid matrix such as agarose beads or magnetic beads, is modified by covalently attaching the ligand to its surface.
2. Application of the sample: The protein mixture is applied to the top of the affinity chromatography column, allowing it to flow through the stationary phase under gravity or pressure.
3. Binding and washing: As the sample flows through the column, the target protein selectively binds to the ligand on the stationary phase, while other proteins and impurities pass through. The column is then washed with a suitable buffer to remove any unbound proteins and contaminants.
4. Elution of the bound protein: The target protein can be eluted from the column using various methods, such as changing the pH, ionic strength, or polarity of the buffer, or by introducing a competitive ligand that displaces the bound protein.
5. Collection and analysis: The eluted protein fraction is collected and analyzed for purity and identity, often through techniques like SDS-PAGE or mass spectrometry.

Affinity chromatography is a powerful tool in biochemistry and molecular biology due to its high selectivity and specificity, enabling the efficient isolation of target proteins from complex mixtures. However, it requires careful consideration of the binding affinity between the ligand and the protein, as well as optimization of the elution conditions to minimize potential damage or denaturation of the purified protein.

Cysteine is a semi-essential amino acid, which means that it can be produced by the human body under normal circumstances, but may need to be obtained from external sources in certain conditions such as illness or stress. Its chemical formula is HO2CCH(NH2)CH2SH, and it contains a sulfhydryl group (-SH), which allows it to act as a powerful antioxidant and participate in various cellular processes.

Cysteine plays important roles in protein structure and function, detoxification, and the synthesis of other molecules such as glutathione, taurine, and coenzyme A. It is also involved in wound healing, immune response, and the maintenance of healthy skin, hair, and nails.

Cysteine can be found in a variety of foods, including meat, poultry, fish, dairy products, eggs, legumes, nuts, seeds, and some grains. It is also available as a dietary supplement and can be used in the treatment of various medical conditions such as liver disease, bronchitis, and heavy metal toxicity. However, excessive intake of cysteine may have adverse effects on health, including gastrointestinal disturbances, nausea, vomiting, and headaches.

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

NHS-coupling gives biotinylation of any primary amines in the protein). Enzymatic biotinylation results in biotinylation of a ... Chemical biotinylation utilises various conjugation chemistries to yield nonspecific biotinylation of amines, carboxylates, ... In contrast to chemical biotinylation methods, enzymatic biotinylation allows biotin to be linked at exactly one residue ... Photoactivatable biotinylation reagents can also be used to activate biotinylation at specific times in an experiment or during ...
Biotinylation basically creates a strong affinity between the biotin on the cytokine-specific antibody and the streptavidin on ... "Biotinylation". ThermoFisher Scientific. Retrieved 6 December 2018. "BCIP/NBT-plus SDS Summary" (PDF). MABTECH. Retrieved 6 ...
Fouda AE, Pflum MK (August 2015). "A Cell-Permeable ATP Analogue for Kinase-Catalyzed Biotinylation". Angewandte Chemie. 54 (33 ... Senevirathne C, Embogama DM, Anthony TA, Fouda AE, Pflum MK (January 2016). "The generality of kinase-catalyzed biotinylation ...
Citrulline residues can be chemically modified with butanedione or by biotinylation prior to analysis, leading to a different ... Tutturen, Astrid E. V.; Holm, Anders; Fleckenstein, Burkhard (2013-11-01). "Specific biotinylation and sensitive enrichment of ...
"Biotinylation by antibody recognition - A method for proximity labeling". Nature Methods. 15 (2): 127-133. doi:10.1038/nmeth. ... "β-Actin mRNA interactome mapping by proximity biotinylation". Proceedings of the National Academy of Sciences. 116 (26): 12863- ...
Biotinylation Siegel L, Foote JL, Coon MJ (March 1965). "The enzymatic synthesis of propionyl coenzyme A holocarboxylase from d ...
... can act as an ATP sensor protein through biotinylation. Biotinylation will immobilize luciferase on the cell-surface ...
2004). "Use of protein biotinylation in vivo for chromatin immunoprecipitation". Analytical Biochemistry. 325 (1): 68-76. doi: ... or in vivo biotinylation can be used instead of antibodies to the native protein of interest. The DNA associated with the ...
Miller, B. T.; Collins, T. J.; Rogers, M. E.; Kurosky, A. (1997). "Peptide biotinylation with amine-reactive esters: ...
Chapman-Smith A, Cronan JE (September 1999). "The enzymatic biotinylation of proteins: a post-translational modification of ...
Chapman-Smith A, Cronan JE (1999). "The enzymatic biotinylation of proteins: a post-translational modification of exceptional ...
ISBN 978-1-118-91840-1. Chapman-Smith A, Cronan JE (September 1999). "The enzymatic biotinylation of proteins: a post- ...
Jander, G; Cronan, J E; Beckwith, J (1996). "Biotinylation in vivo as a sensitive indicator of protein secretion and membrane ...
Protein biotinylation in vivo was proposed to alleviate the problems caused by frequent incompatibility of antibody staining ... Viens, A.; Harper, F.; Pichard, E.; Comisso, M.; Pierron, G.; Ogryzko, V. (2008). "Use of Protein Biotinylation in Vivo for ...
The biotinylation motif Met-Lys-Met is located at the tip of the β-hairpin structure. Rotations around the CαCβ bond of this ... Removal of the thumb by mutagenesis rendered BCCP-87 a favorable substrate for lipoylation but abolished biotinylation (Reche ...
Streptavidin Biotinylation Helppolainen SH, Nurminen KP, Määttä JA, Halling KK, Slotte JP, Huhtala T, et al. (August 2007). " ...
Biotinylation of histone proteins in nuclear chromatin plays a role in chromatin stability and gene expression. The US National ... Biotinylation of histone proteins in nuclear chromatin is a posttranslational modification that plays a role in chromatin ... Biotin deficiency Biotin sulfoxide Biotinidase deficiency Biotinylation Multiple carboxylase deficiency NeutrAvidin Photobiotin ... the chemically modified biotin reagents are bound to the targeted compounds in a solution via a process called biotinylation. ...
Immunofluorescence Biomolecular engineering Biotinylation SpyTag/SpyCatcher Unnatural amino acids Bioconjugate Chemistry ...
The advent of proximity biotinylation by birA* has facilitated the first proteomics-based studies of the cadherin adhesome. ...
... biotinylation or glucose decomposition. Typically, the primary building blocks of these nanostructures are individual ...
biotinylation: covalent attachment of a biotin moiety using a biotinylation reagent, typically for the purpose of labeling a ...
Subtiligase biotinylation of N-termini uses enzymatic labeling of N-terminal peptides, but does not use lysine blocking ... Lysine guanidination followed by biotinylation of N-termini uses a chemical to block lysine residues and tag free N-termini. ... Acetylation of amines followed by tryptic digestion and biotinylation of free N-terminal peptides uses chemical (acetylation) ...
"Identification of new accessible tumor antigens in human colon cancer by ex vivo protein biotinylation and comparative mass ...
In 2009, one idea has been to attach the exonuclease to the nanopore, perhaps through biotinylation to the beta barrel ...
Limitations For Chem-seq to be feasible, the small molecule under study must be amenable to biotinylation without disruption of ...
Biotinylation of DNA and RNA with photoactivatable biotin is easier and less expensive than enzymatic methods since the DNA and ...
The dye nucleotide to be used will likely occur by treatment with a phosphorylation enzyme and biotinylation and reaction of ...
... thereby increasing the abundance of histone H4 biotinylation marks in HEK-293 human kidney cells". The Journal of Nutritional ...
The tag is recognized by a repertoire of single-domain antibodies AviTag, a peptide allowing biotinylation by the enzyme BirA ... such as biotinylation by biotin ligase) or chemical modification (such as coupling to other proteins through SpyCatcher or ...
... biotinylation MeSH E05.393.525.100 - blotting, northern MeSH E05.393.525.150 - blotting, southern MeSH E05.393.525.225 - ...
NHS-coupling gives biotinylation of any primary amines in the protein). Enzymatic biotinylation results in biotinylation of a ... Chemical biotinylation utilises various conjugation chemistries to yield nonspecific biotinylation of amines, carboxylates, ... In contrast to chemical biotinylation methods, enzymatic biotinylation allows biotin to be linked at exactly one residue ... Photoactivatable biotinylation reagents can also be used to activate biotinylation at specific times in an experiment or during ...
Targeting protein biotinylation enhances tuberculosis chemotherapy. Divya Tiwari, Sae Woong Park, Maram M. Essawy, Surendra ... Dive into the research topics of Targeting protein biotinylation enhances tuberculosis chemotherapy. Together they form a ...
ChromaLINK® One-Shot™ Antibody Biotinylation Kit. Catalog #: B-9007-009K. Unit Size: 1 Kit ...
Surface biotinylation.. Biotinylation assays were performed using the Cell Surface Protein Isolation kit (Pierce). Surface ...
Biotinylation of M. ulcerans Genomic DNA Fragments. Figure 1. Figure 1. Distribution of outlier signals among the 30 ...
Studies have shown that biotinylation of histones may play a role in gene expression. Multiple sites that bind to biotin have ... 3] The enzyme holocarboxylase synthetase (HCLS ) catalyzes the addition of biotin (biotinylation) to the inactive apoform, ... As discussed earlier, the enzyme HCLS is required for the biotinylation of the apocarboxylase enzymes into the active ... Once absorbed, biotin becomes available for various biotinylation processes. Biotin binds to each of the 5 apocarboxylases to ...
1999 Poster: EX-Link Biotinylation Reagent Selection Guide. 1999 Nuclear Extracts. 1999 B-Gal Reporter Assay: Mammalian. 1999 B ... 2006 Sulfo-NHS and Sulfo-NHS-LC Biotinylation Kits. Undated Protein Conjugation. Undated Solubilization. Undated ChromatoFlo ...
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Measuring Plasma Membrane Protein Endocytic Rates by Reversible Biotinylation Journal (Biology). Generating a Humanized ...
Thermo Scientific EZ-Link Alkoxyamine-PEG12-Biotin is a biotinylation reagent containing a long, 12-unit polyethylene glycol ( ... Biotinylation reagents differ in reactivity, length, solubility, cell permeability and cleavability. Hydrazides and ... Thermo Scientific EZ-Link Alkoxyamine-PEG12-Biotin is a biotinylation reagent containing a long, 12-unit polyethylene glycol ( ...
2017). Proximity Biotinylation as a Method for Mapping Proteins Associated with mtDNA in Living Cells. Cell Chemical Biology 24 ... as biotinylation occurs in vivo, the possibility to do stringent washes to reduce contaminants and increase solubility of ... showing biotinylation pattern and presence of intact turboID fusion constructs. Samples refer to input before purification. c. ... Establishment of Proximity-Dependent Biotinylation Approaches in Different Plant Model Systems. The Plant Cell 32, 3388-3407. ...
Recombinant human RPS3A protein, fused to His-tag at N-terminus, was expressed in E. coli and purified by using conventional chromatography techniques.
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Metabolic biotinylation of intracellular and secreted proteins as well as surface receptors in mammalian cells provides a ... Here, we show that metabolic biotinylation of proteins fused to the bacterial biotin acceptor peptides (BAP) varies among ...
... for linear amplification and biotinylation of each transcript.. ...
4.6.4 Purification and biotinylation of expressed proteins........... 156. 4.6.5 Synthesis of synthetic lipid bilayer surfaces ...
In my thesis I used a comparative proximity biotinylation proteomics approach of isolated sphingomyelin (SM)-rich secretory ... In my thesis I used a comparative proximity biotinylation proteomics approach of isolated sphingomyelin (SM)-rich secretory ...
When appropriate, in vivo biotinylation of tumor vasculature (26) was performed 5 days after RP6530 treatment and 3 hours after ...
Biotin Labeling / Biotinylation. * What is Biotinylation?. March 12, 2020 Lipid. * What are Fluorescent Lipids?. March 26, 2024 ...
Lysines can be used to increase peptide solubility or to allow for biotinylation. Alternatively, amino acid residues located at ...
... Photochemical transformations are usually orthogonal to classical chemical transformations, a characteristic that renders them a valuable tool for chemists. This booklet describes our whole range of innovative photoactivated compounds, as w
What is Biotinylation Biotinylation, a widely used biological technique, involves the covalent attachment of biotin to ... Customized Synthesis Services for Biotinylation Reagents. Alfa Chemistry, a globally recognized chemical supplier, has recently ... announced its expanded range of services for customized synthesis of biotinylation reagents. ...
The level of antibody biotinylation at which successful blood clearance could be achieved was first established using a 125I ...
In Vivo Biotinylation in E.coli. Determined during production process. Recombinant Aspergillus oryzae Actin (act1). CSB- ... In Vivo Biotinylation in E.coli. Determined during production process. Recombinant Salinibacter ruber Acylphosphatase (acyP). ... In Vivo Biotinylation in E.coli. Determined during production process. Recombinant Bovine ADP-ribosylation factor-like protein ... In Vivo Biotinylation in E.coli. Determined during production process. Recombinant Oryza sativa subsp. japonica Auxin response ...
This product is not recommended for use under denaturing conditions in WB. We would suggest testing it under native conditions. Denaturing and reducing conditions will greatly diminish reactivity and selectivity of this antibody. Abcam does not test ab34710 with endogenous samples in WB. We do recommend to look at the guidelines for blotting large proteins here.. ab34710 has ,5% cross-reactivity with Collagen III. Customers have been successful using ab34710 in this application, please see references below (Tillgren V et al. J Biol Chem 290:918-25; 2015).. Positive Control: Human stomach, skin and adrenal gland tissue lysates. ...
... biotinylation, and succinylation. Scales range from milligram to muti-gram quantities. All peptides include HPLC and Mass ...
We used cell surface biotinylation to isolate plasma membrane proteins of rEPDC and hASC, Nano-liquid chromatography with ...
... optimising expression of soluble protein domains and in vivo biotinylation. New Biotechnology, 29 (5). pp. 515-525. ISSN 1876- ...
Additionally, cell surface biotinylation assays showed that, whereas the A3AR was internalised rapidly following R-PIA exposure ...
Biotinylation of Cell Surface Proteins for Microscopic and Proteomic PPARα Antagonist drug Analyses4.1. Biotinylation. ... SGCs without the need of biotinylation have been employed as controls. 4.2. Confocal fluorescent microscopic examinations. To ... The biotinylation reaction was terminated with 50 mM glycine at 4uC for 15 min. Cells were then pelleted (1006g for 5 min at ... check no matter whether biotinylation was prosperous on the SGC surfaces, 16106 biotinylated SGCs (16106 non-biotinylated SGCs ...
  • In biochemistry, biotinylation is the process of covalently attaching biotin to a protein, nucleic acid or other molecule. (wikipedia.org)
  • Biotinylation is rapid, specific and is unlikely to disturb the natural function of the molecule due to the small size of biotin (MW = 244.31 g/mol). (wikipedia.org)
  • Enzymatic biotinylation results in biotinylation of a specific lysine within a certain sequence by a bacterial biotin ligase. (wikipedia.org)
  • Most chemical biotinylation reagents consist of a reactive group attached via a linker to the valeric acid side chain of biotin. (wikipedia.org)
  • As the biotin binding pocket in avidin / streptavidin is buried beneath the protein surface, biotinylation reagents possessing a longer linker are desirable, as they enable the biotin molecule, once it has been attached to its target, to be more accessible to binding avidin/streptavidin/Neutravidin protein. (wikipedia.org)
  • In contrast to chemical biotinylation methods, enzymatic biotinylation allows biotin to be linked at exactly one residue present in the protein. (wikipedia.org)
  • Enzymatic biotinylation is most often carried out by E. coli biotin holoenzyme synthetase, also known as biotin ligase (BirA, P06709). (wikipedia.org)
  • Once tagged, the protein is then incubated with BirA allowing biotinylation to take place in the presence of biotin and ATP. (wikipedia.org)
  • The plasmid contained a biotin-acceptor coding sequence fused in-frame with the apoaequorin gene as well as the birA gene, encoding biotin protein ligase (BPL), responsible for post-translational biotinylation. (uwindsor.ca)
  • Other sources of experimental information include X-ray diffraction, biotinylation, sequence mutation and deletion, solution binding and chemical cross-linking data. (lu.se)
  • NHS-coupling gives biotinylation of any primary amines in the protein). (wikipedia.org)
  • Enzymatic biotinylation can also take place in vivo typically through the co-expression of an Avitag tagged protein and BirA. (wikipedia.org)
  • Enzymatic biotinylation can be carried out in vitro but BirA also reacts specifically with its target peptide inside mammalian and bacterial cells and at the cell surface, while other cellular proteins are not modified. (wikipedia.org)
  • Because of the hydrophobicity of NHS-esters, NHS biotinylation reagents can also diffuse through the cell membrane, meaning that they will biotinylate both internal and external components of a cell. (wikipedia.org)
  • Additionally, cell surface biotinylation assays showed that, whereas the A3AR was internalised rapidly following R-PIA exposure (t1/2= 10 min), the agonist-dependent loss of A1AR from the cell surface was much slower (t1/2= 90 min) and less complete. (gla.ac.uk)
  • Chemical biotinylation utilises various conjugation chemistries to yield nonspecific biotinylation of amines, carboxylates, sulfhydryls and carbohydrates (e.g. (wikipedia.org)
  • Protein biotinylation is a key post-translational modification found throughout the living world. (nih.gov)
  • This modification is distinctive, in that it is carried out by a single enzyme: biotin protein ligase (BPL), an enzyme that is able to biotinylate multiple target substrates without aberrant-off target biotinylation. (nih.gov)
  • Phospholipid biotinylation of polydimethylsiloxane (PDMS) for protein immobilization. (bvsalud.org)
  • The aim is tested in rodent models (rat, KCNMB1 K/0 mouse) using both in vitro (Western-blotting, protein biotinylation, ICC/IF microscopy, patch-clamp, cDNA reverse-permeabilization, and isolated myocytes and arteries) and in vivo methods (closed cranial window, intravital microscopy). (nih.gov)
  • To complement prior work and fully characterize all phosphorylated proteins after the stimulation of cell signaling, we developed K-BMAPS (kinase-catalyzed biotinylation to map signaling), which utilizes ATP-biotin as a kinase cosubstrate to biotin label substrates. (nih.gov)
  • It might also have the ability to attach biotin to certain proteins through a process called biotinylation. (medlineplus.gov)
  • Within the nucleus, biotinylation of DNA-associated proteins called histones may help determine whether certain genes are turned on or off. (medlineplus.gov)
  • Surface membrane proteins of viable, intact cells were subjected to biotinylation then affinity-captured and purified on monomeric avidin columns. (nih.gov)
  • Multiple methods have been used, such as biotinylation of RNA and immobilization on streptavidin sepharose. (nih.gov)