title: Peptide substrates for chymosin (rennin). Kinetic studies with bovine kappa-casein-(103-108)-hexapeptide analogues.
abstract: Kinetic parameters have been determined for the reaction between chymosin (EC 3.4.23.4) and synthetic peptide analogues of the sequence Leu-Ser-Phe-Met-Ala-Ile around the chymosin-sensitive Phe(105)-Met(106) bond of bovine kappa-casein. From the present and earlier results it is concluded that a minimum length of the molecular backbone with three amino acid units on both sides of the scissile bond is required to make the peptide a good substrate for the enzyme. In addition, hydrophobic side chains in the positions 103 and 108, and particularly the hydroxyl group of Ser-104 contribute to the effectiveness of the enzyme-substrate interactions. The substrate properties are markedly influenced by changes in the steric and/or polar character of the amino acid side chains in the positions 105 and 106.
mesh_terms: D002364:Caseins / Q000031:analogs & derivatives* / Q000378:metabolism; D012085:Chymosin / Q000378:metabolism*; D007700:Kinetics; D009842:Oligopeptides / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D002364:Caseins; D009842:Oligopeptides; D012085:Chymosin