title: Specificity of an extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine alpha s1-casein.
abstract: The specificity of the extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine alpha s1-casein was studied. Hydrolysis was monitored over time by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE) and urea-PAGE. The major pH 4.6-soluble peptides were isolated by high-performance liquid chromatography and identified by N-terminal amino acid sequencing and mass spectrometry. The time course of peptide formation indicated that His-8-Gln-9, Ser-161-Gly-162, and either Gln-172-Tyr-173 or Phe-23-Phe-24 were the first, second, and third bonds cleaved, respectively. Other cleavage sites included Asn-19-Leu-20, Phe-32-Gly-33, Tyr-104-Lys-105, Leu-142-Ala-143, Phe-150-Arg-151, Gln-152-Phe-153, Leu-169-Gly-170, and Thr-171-Gln-172. The proteinase had a broad specificity for the amino acid residues at the P1 and P'1 positions but showed a preference for hydrophobic residues at the P2, P3, P4, P'2, P'3, and P'4 positions.
authors.affiliation: Department of Food Chemistry, University College, Cork, Ireland. DYDK6010@IRUCCVAX.UCC.IE
authors.forename: F P
authors.initials: FP
authors.lastname: Rattray
authors.forename: P F
authors.initials: PF
authors.lastname: Fox
authors.forename: A
authors.initials: A
authors.lastname: Healy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001951:Brevibacterium / Q000201:enzymology*; D002364:Caseins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D010450:Endopeptidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D002364:Caseins; D010446:Peptide Fragments; D010450:Endopeptidases