title: Use of a molybdenum(VI) complex as artificial protease in protein photocleavage.
abstract: In this study, a molybdenum(VI) peroxo α-amino acid complex, MoO(O2)2(α-leucine) (H2O), was prepared and used as an artificial protease for site-specific cleavage of porcine pepsin, a model protein. Cleavage of pepsin by MoO(O2)2(α-leucine) (H2O) was achieved under photochemical conditions at room temperature and pH 7.0. The reaction was activated by irradiation of the MoO(O2)2(α-leucine) (H2O)-protein mixture by UV light (320 and 340nm) for up to 30min. No cleavage was observed in the absence of MoO(O2)2(α-leucine) (H2O) or the light. The photocleavage yield increased with irradiation time. The cleaved fragments were sequencable, and the cleavage site was assigned to Leu(112)-Tyr(113). The cleavage reaction was quenched by ethanol. Therefore, hydroxyl radicals may be involved in the reaction and responsible for the cleavage of the protein. This is the first demonstration of the successful photocleavage of proteins by a molybdenum complex. This observation can provide a new approach for the photochemical footprinting of metal binding sites on proteins.
authors.affiliation: Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Bangkok 10110, Thailand.
authors.forename: Benchawan
authors.initials: B
authors.lastname: Jityuti
authors.forename: Teerayuth
authors.initials: T
authors.lastname: Liwporncharoenvong
authors.forename: Apinya
authors.initials: A
authors.lastname: Buranaprapuk
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D040761:Biomimetic Materials / Q000737:chemistry / Q000378:metabolism*; D000431:Ethanol / Q000737:chemistry; D008982:Molybdenum / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry / Q000378:metabolism*; D010434:Pepsin A / Q000737:chemistry / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D055668:Photochemical Processes; D059748:Proteolysis; D013379:Substrate Specificity; D013552:Swine
chemical_list: D009942:Organometallic Compounds; D000431:Ethanol; D008982:Molybdenum; D010447:Peptide Hydrolases; D010434:Pepsin A
keywords: Cleavage reactions; Molybdenum complex; Pepsin; Protein–metal interactions; Transition metals