title: Specificity of an extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine beta-casein.
abstract: The specificity of the extracellular proteinase from Brevibacterium linens ATCC 9174 on bovine beta-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 major sites of hydrolysis were Ser-18-Ser-19, Glu-20-Glu-21, Gln-56-Ser-57, Gln-72-Asn-73, Leu-77-Thr-78, Ala-101-Met-102, Phe-119-Thr-120, Leu-139-Leu-140, Ser-142-Trp-143, His-145-Gln-146, Gln-167-Ser-168, Gln-175-Lys-176, Tyr-180-Pro-181, and Phe-190-Leu-191. The proteinase had a broad specificity for the amino acid residues present 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 / Q000378:metabolism*; D002417:Cattle; D002611:Cheese / Q000382:microbiology; D010450:Endopeptidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D002364:Caseins; D010446:Peptide Fragments; D010450:Endopeptidases