Chymotrypsin (EC 3.4.21.1, chymotrypsins A and B, alpha-chymar ophth, avazyme, chymar, chymotest, enzeon, quimar, quimotrase, alpha-chymar, alpha-chymotrypsin A, alpha-chymotrypsin) is a digestive enzyme component of pancreatic juice acting in the duodenum, where it performs proteolysis, the breakdown of proteins and polypeptides. Chymotrypsin preferentially cleaves peptide amide bonds where the side chain of the amino acid N-terminal to the scissile amide bond (the P1 position) is a large hydrophobic amino acid (tyrosine, tryptophan, and phenylalanine). These amino acids contain an aromatic ring in their side chain that fits into a hydrophobic pocket (the S1 position) of the enzyme. It is activated in the presence of trypsin. The hydrophobic and shape complementarity between the peptide substrate P1 side chain and the enzyme S1 binding cavity accounts for the substrate specificity of this enzyme. Chymotrypsin also hydrolyzes other amide bonds in peptides at slower rates, particularly those containing leucine at the P1 position.
Tryptophan synthase or tryptophan synthetase is an enzyme that catalyses the final two steps in the biosynthesis of tryptophan. It is commonly found in Eubacteria, Archaebacteria, Protista, Fungi, and Plantae. However, it is absent from Animalia. It is typically found as an α2β2 tetramer. The α subunits catalyze the reversible formation of indole and glyceraldehyde-3-phosphate (G3P) from indole-3-glycerol phosphate (IGP). The β subunits catalyze the irreversible condensation of indole and serine to form tryptophan in a pyridoxal phosphate (PLP) dependent reaction. Each α active site is connected to a β active site by a 25 angstrom long hydrophobic channel contained within the enzyme. This facilitates the diffusion of indole formed at α active sites directly to β active sites in a process known as substrate channeling. The active sites of tryptophan synthase are allosterically coupled.
Nonribosomal peptides (NRP) are a class of peptide secondary metabolites, usually produced by microorganisms like bacteria and fungi. Nonribosomal peptides are also found in higher organisms, such as nudibranchs, but are thought to be made by bacteria inside these organisms. While there exist a wide range of peptides that are not synthesized by ribosomes, the term nonribosomal peptide typically refers to a very specific set of these as discussed in this article.
Oligosaccharyltransferase or OST (EC 2.4.1.119) is a membrane protein complex that transfers a 14-sugar oligosaccharide from dolichol to nascent protein. It is a type of glycosyltransferase. The sugar Glc3Man9GlcNAc2 (where Glc=Glucose, Man=Mannose, and GlcNAc=N-acetylglucosamine) is attached to an asparagine (Asn) residue in the sequence Asn-X-Ser or Asn-X-Thr where X is any amino acid except proline. This sequence is called a glycosylation sequon. The reaction catalyzed by OST is the central step in the N-linked glycosylation pathway.
N-Formylmethionine is a derivative of the amino acid methionine in which a formyl group has been added to the amino group. It is specifically used for initiation of protein synthesis from bacterial and organellar genes, and may be removed post-translationally.
Formylation refers to any chemical processes in which a compound is functionalized with a formyl group (-CH=O). In organic chemistry, the term is most commonly used with regards to aromatic compounds. In biochemistry the reaction is catalysed by enzymes such as formyltransferases.
Prolyl endopeptidase (PE) also known as prolyl oligopeptidase or post-proline cleaving enzyme is an enzyme that in humans is encoded by the PREP gene.
10-Formyltetrahydrofolate (10-CHO-THF) is a form of tetrahydrofolate that acts as a donor of formyl groups in anabolism. In these reactions 10-CHO-THF is used as a substrate in formyltransferase reactions.
Coagulation factor XIII A chain is a protein that in humans is encoded by the F13A1 gene.
Acireductone dioxygenase (Ni2+-requiring) (EC 1.13.11.53) is an enzyme that catalyzes the chemical reaction
Methionine aminopeptidase 2 is an enzyme that in humans is encoded by the METAP2 gene.
In enzymology, a formate—tetrahydrofolate ligase is an enzyme that catalyzes the chemical reaction
In enzymology, a formylaspartate deformylase (EC 3.5.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a formylmethionine deformylase (EC 3.5.1.31) is an enzyme that catalyzes the chemical reaction
In enzymology, a N-formylmethionylaminoacyl-tRNA deformylase (EC 3.5.1.27) is an enzyme that catalyzes the chemical reaction
In enzymology, a formylmethanofuran-tetrahydromethanopterin N-formyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a glycylpeptide N-tetradecanoyltransferase is an enzyme that catalyzes the chemical reaction
Methionine aminopeptidase 1 is an enzyme that in humans is encoded by the METAP1 gene.
Ilomastat (INN), is a broad-spectrum matrix metalloproteinase inhibitor.
N-formylmethionyl-peptidase is an enzyme. This enzyme catalyses the following chemical reaction
