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Pyroglutamate Aminopeptidase
Pyroglutamate aminopeptidase is a type of enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ... that cleaves the peptide bond linking the N-terminal end of a polypeptide forming a cyclical lactam to the next amino acid residue. This cyclic structure protects the polypeptide from degradation but renders the protein difficult to analyze in the laboratory. Pyroglutamate aminopeptidase may be used to cleave the cyclical lactam and will therefore leave the next amino acid with a free N-terminal. See also * Pyroglutamyl-peptidase I * Pyroglutamyl-peptidase II References {{Portal bar, Biology, border=no Proteases EC 3.4 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Bond
In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 (carbon number one) of one alpha-amino acid and N2 (nitrogen number two) of another, along a peptide or protein chain. It can also be called a eupeptide bond to distinguish it from an isopeptide bond, which is another type of amide bond between two amino acids. Synthesis When two amino acids form a ''dipeptide'' through a ''peptide bond'', it is a type of condensation reaction. In this kind of condensation, two amino acids approach each other, with the non-side chain (C1) carboxylic acid moiety of one coming near the non-side chain (N2) amino moiety of the other. One loses a hydrogen and oxygen from its carboxyl group (COOH) and the other loses a hydrogen from its amino group (NH2). This reaction produces a molecule of water (H2O) and two amino acids joined by a peptide bond (−CO−NH−). The two joined amino acids are called a dipeptide. The am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactam
A lactam is a cyclic amide, formally derived from an amino alkanoic acid. The term is a portmanteau of the words ''lactone'' + ''amide''. Nomenclature Greek prefixes in alphabetical order indicate ring size: * α-Lactam (3-atom rings) * β-Lactam (4-atom rings) * γ-Lactam (5-atom rings) * δ-Lactam (6-atom rings) * ε-Lactam (7-atom rings) This ring-size nomenclature stems from the fact that a hydrolyzed α-Lactam leads to an α-amino acid and a β-Lactam to a β-amino acid, ''etc''. Synthesis General synthetic methods exist for the organic synthesis of lactams. Beckmann rearrangement Lactams form by the acid-catalyzed rearrangement of oximes in the Beckmann rearrangement. Schmidt reaction Lactams form from cyclic ketones and hydrazoic acid in the Schmidt reaction. Cyclization of amino acids Lactams can be formed from cyclisation of amino acids via the coupling between an amine and a carboxylic acid within the same molecule. Lactamization is most efficient in this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroglutamyl-peptidase I
Pyroglutamyl-peptidase I (, also known as Pyrrolidonyl peptidase, is an enzyme (a cysteine peptidase) found in bacteria, plants and animals. It can be used to distinguish certain Streptococcal organisms. Other names are ''5-oxoprolyl-peptidase'', ''pyrase'', ''pyrrolidonyl arylamidase'', ''pyroglutamate aminopeptidase'', ''pyroglutamyl aminopeptidase'', ''L-pyroglutamyl peptide hydrolase'', ''pyrrolidone-carboxyl peptidase'', ''pyrrolidone-carboxylate peptidase'', '' pyrrolidonyl peptidase'', ''L-pyrrolidonecarboxylate peptidase'', ''pyroglutamidase'', ''pyrrolidonecarboxylyl peptidase'') is an enzyme. This enzyme catalyses the following chemical reaction : Release of an N-terminal pyroglutamyl group from a polypeptide, the second amino acid generally not being Pro Pro is an abbreviation meaning "professional". Pro, PRO or variants thereof may also refer to: People * Miguel Pro (1891–1927), Mexican priest * Pro Hart (1928–2006), Australian painter * Mlungisi Mdluli (bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroglutamyl-peptidase II
Pyroglutamyl-peptidase II (, ''thyroliberinase'', ''pyroglutamyl aminopeptidase II'', ''thyrotropin-releasing factor pyroglutamate aminopeptidase'', ''pyroglutamate aminopeptidase II'', ''pyroglutamyl peptidase II'', ''thyroliberin-hydrolyzing pyroglutamate aminopeptidase'', ''thyrotropin-releasing hormone-degrading pyroglutamate aminopeptidase'', ''thyrotropin-releasing hormone-degrading peptidase'', ''TRH aminopeptidase'') is an enzyme. This enzyme catalyses the following chemical reaction : Release of the N-terminal pyroglutamyl group from pGlu--His-Xaa tripeptides and pGlu--His-Xaa-Gly tetrapeptides This enzyme is highly specific for thyrotropin releasing hormone Thyrotropin-releasing hormone (TRH) is a hypophysiotropic hormone produced by neurons in the hypothalamus that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary. TRH has been used clinicall .... Human gene TRHDE - thyrotropin releasing hormone degrading e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteases
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks bonds. Proteases are involved in many biological functions, including digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Hierarchy of proteases Based on catalytic residue Proteases can be classified into seven broad groups: * Serine proteases - ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
