title: The synthesis of inhibitors for processing proteinases and their action on the Kex2 proteinase of yeast.
abstract: Peptidyl chloromethane and sulphonium salts containing multiple Arg and Lys residues were synthesized as potential inhibitors of prohormone and pro-protein processing proteinases. The potencies of these compounds were assayed by measuring the kinetics of inactivation of the yeast Kex2 proteinase, the prototype of a growing family of eukaryotic precursor processing proteinases. The most potent inhibitor, Pro-Nvl-Tyr-Lys-Arg-chloromethane, was based on cleavage sites in the natural Kex2 substrate pro-alpha-factor. This inhibitor exhibited a Ki of 3.7 nM and a second-order inactivation rate constant (k2/Ki) of 1.3 x 10(7) M-1.s-1 comparable with the value of kcat./Km obtained with Kex2 for the corresponding peptidyl methylcoumarinylamide substrate. The enzyme exhibited sensitivity to the other peptidyl chloromethanes over a range of concentrations, depending on peptide sequence and alpha-amino decanoylation, but was completely resistant to peptidyl sulphonium salts. Kinetics of inactivation by these new inhibitors of a set of 'control' proteinases, including members of both the trypsin and subtilisin families, underscored the apparent specificity of the compounds most active against Kex2 proteinase.
authors.affiliation: Friedrich Miescher-Institut, Basel, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Angliker
authors.forename: P
authors.initials: P
authors.lastname: Wikstrom
authors.forename: E
authors.initials: E
authors.lastname: Shaw
authors.forename: C
authors.initials: C
authors.lastname: Brenner
authors.forename: R S
authors.initials: RS
authors.lastname: Fuller
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000138:chemical synthesis* / Q000494:pharmacology; D000595:Amino Acid Sequence; D001665:Binding Sites; D007700:Kinetics; D008969:Molecular Sequence Data; D043484:Proprotein Convertases; D011480:Protease Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D029701:Saccharomyces cerevisiae Proteins; D013381:Subtilisins / Q000037:antagonists & inhibitors*; D015003:Yeasts / Q000201:enzymology*
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D011480:Protease Inhibitors; D029701:Saccharomyces cerevisiae Proteins; D043484:Proprotein Convertases; D013381:Subtilisins; C058751:KEX2 protein, S cerevisiae