title: Application of Schiff base copper(II) and iron(III) chelates to site-specific cleavage of a trypsin.
abstract: Amidine-containing Schiff base iron(III) and copper(II) chelates were prepared from alpha-amino acid, metal ion, and salicylaldehyde. These chelates behaved as specific inhibitors of trypsin, with Ki values in the range 10(-5)-10(-6) M. Selective cleavage of the trypsin backbone resulting from specific binding of the chelate to the trypsin active site was investigated. Cleavage was observed when trypsin was incubated with amidine-containing copper(II) or iron(III) chelate, H2O2, and ascorbate. Examination of the three-dimensional structure of trypsin suggests that cleavage occurred at a peptide bond within the Gly195-Ala204 sequence.
authors.affiliation: Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Toyota
authors.forename: H
authors.initials: H
authors.lastname: Miyazaki
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.forename: H
authors.initials: H
authors.lastname: Sekizaki
authors.forename: K
authors.initials: K
authors.lastname: Tanizawa
mesh_terms: D000578:Amidines / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D002412:Cations; D002614:Chelating Agents / Q000378:metabolism / Q000494:pharmacology*; D003300:Copper / Q000378:metabolism / Q000494:pharmacology*; D005290:Ferric Compounds / Q000378:metabolism / Q000494:pharmacology*; D007502:Iron Chelating Agents / Q000378:metabolism* / Q000494:pharmacology*; D007700:Kinetics; D009942:Organometallic Compounds / Q000378:metabolism / Q000494:pharmacology*; D012545:Schiff Bases / Q000378:metabolism / Q000494:pharmacology*; D013379:Substrate Specificity; D014357:Trypsin / Q000187:drug effects / Q000378:metabolism*