title: Specificity and kinetic studies on the cleavage of various prohormone mono- and paired-basic residue sites by yeast aspartic protease 3.
abstract: The specificity and relative efficiency of cleavage of mono- and paired-basic residue processing sites by YAP3p was determined in vitro for a number of prohormone substrates: human ACTH1 39, bovine proinsulin, porcine cholecystokinin 33, cholecystokinin (CCK) 13-33, dynorphin A(1-11), dynorphin B(1-13), and amidorphin. YAP3p generated ACTH1-15 from ACTH1-39. It cleaved proinsulin at the paired-basic residue sites of the B-C junction as well as the C-A junction. Leu-enkephalin-Arg and Leu-enkephalin-Arg-Arg were generated from dynorphin A and dynorphin B, respectively. YAP3p generated Met-enkephalin-Lys-Lys from amidorphin showing that cleavage by this enzyme can occur at a lone pair of Lys residues. CCK33 was cleaved at Lys23 and Arg9, each containing an upstream Arg residue at the P6 and P5 position, respectively. Km values were between 10(-4) and 10(-5) M for the various substrates, with the highest affinity exhibited for the tetrabasic site of ACTH1-39 (1.8 x 10(-5) M). The tetrabasic residue site of ACTH1-39 was cleaved with the highest relative efficiency (kcat/Km = 3.1 x 10(6) m-1 s-1), while that of the monobasic site of CCK13-33 and the paired-basic site of proinsulin B-C junction, were cleaved less efficiently at 4.2 x 10(4) m-1 s-1 and 1.6 x 10(4) m-1 s-1, respectively.
authors.affiliation: Laboratory of Developmental Neurobiology and the Endocrinology and Reproduction Research Branch, NICHD, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: N X
authors.initials: NX
authors.lastname: Cawley
authors.forename: H C
authors.initials: HC
authors.lastname: Chen
authors.forename: M C
authors.initials: MC
authors.lastname: Beinfeld
authors.forename: Y P
authors.initials: YP
authors.lastname: Loh
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D002417:Cattle; D002766:Cholecystokinin / Q000378:metabolism; D004399:Dynorphins / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D011384:Proinsulin / Q000378:metabolism; D011489:Protein Denaturation; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity
chemical_list: D005656:Fungal Proteins; D010446:Peptide Fragments; D029701:Saccharomyces cerevisiae Proteins; D004399:Dynorphins; D000324:Adrenocorticotropic Hormone; D002766:Cholecystokinin; D011384:Proinsulin; C022325:aspartic proteinase A; D016282:Aspartic Acid Endopeptidases; C499266:YPS1 protein, S cerevisiae