title: A membrane-bound, calcium-dependent protease in yeast alpha-cell cleaving on the carboxyl side of paired basic residues.
abstract: Paired basic residues are known as a typical site for proteolytic processing of precursors of bioactive peptides. By using a fluorogenic substrate Boc-Gln-Arg-Arg-MCA, a unique endoprotease exhibiting hydrolytic specificity toward the carboxyl side of paired basic residues was partially purified (about 4600-fold) from the membrane fraction of yeast Saccharomyces cerevisiae alpha-cells. The enzyme is a calcium-dependent thiol protease, with optimal pH at 7.0. It is a glycoprotein, with an apparent molecular weight of about 100,000-120,000. It cleaves fluorogenic substrates and a synthetic model peptide at the carboxyl side of paired basic residues. From its unique substrate specificity, this enzyme may be involved in precursor processing in vivo.
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D002462:Cell Membrane / Q000201:enzymology; D003546:Cysteine Endopeptidases; D010450:Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D011480:Protease Inhibitors / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D011480:Protease Inhibitors; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D002118:Calcium