title: Selective cleavage of pepsin by molybdenum metallopeptidase.
abstract: In this study, the cleavage of protein by molybdenum cluster is reported for the first time. The protein target used is porcine pepsin. The data presented in this study show that pepsin is cleaved to at least three fragments with molecular weights of ∼23, ∼19 and ∼16 kDa when the mixture of the protein and ammonium heptamolybdate tetrahydrate ((NH(4))(6)Mo(7)O(24)·4H(2)O) was incubated at 37°C for 24h. No self cleavage of pepsin occurs at 37 °C, 24h indicating that the reaction is mediated by the metal ions. N-terminal sequencing of the peptide fragments indicated three cleavage sites of pepsin between Leu 112-Tyr 113, Leu 166-Leu 167 and Leu 178-Asn 179. The cleavage reaction occurs after incubation of the mixture of pepsin and (NH(4))(6)Mo(7)O(24)·4H(2)O) only for 2h. However, the specificity of the cleavage decreases when incubation time is longer than 48 h. The mechanism for cleavage of pepsin is expected to be hydrolytic chemistry of the amide bonds in the protein backbone.
authors.affiliation: Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Bangkok 10110, Thailand.
authors.forename: Sudarat
authors.initials: S
authors.lastname: Yenjai
authors.forename: Pinpinat
authors.initials: P
authors.lastname: Malaikaew
authors.forename: Teerayuth
authors.initials: T
authors.lastname: Liwporncharoenvong
authors.forename: Apinya
authors.initials: A
authors.lastname: Buranaprapuk
mesh_terms: D000818:Animals; D001216:Asparagine / Q000737:chemistry; D006358:Hot Temperature; D007930:Leucine / Q000737:chemistry; D045726:Metalloproteases / Q000737:chemistry*; D008982:Molybdenum / Q000737:chemistry*; D010434:Pepsin A / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D020539:Sequence Analysis, Protein; D013552:Swine; D014443:Tyrosine / Q000737:chemistry
chemical_list: D010446:Peptide Fragments; D014443:Tyrosine; D001216:Asparagine; D008982:Molybdenum; D045726:Metalloproteases; D010434:Pepsin A; D007930:Leucine; C022175:ammonium molybdate