title: Biochemical analysis of the yeast proteinase inhibitor (IC) homolog ICh and its comparison with IC.
abstract: Carboxypeptidase Y (CPY) inhibitor (I(C)) and its homologous protein (I(C)h) are thought to be members of the phosphatidylethanolamine-binding protein (PEBP) family of Saccharomyces cerevisiae. The biochemical characterization of I(C) and its inhibition mode toward CPY were recently reported, but I(C)h has not been characterized. The molecular mass of I(C)h was determined to be 22,033.7. The N-terminal Met1 was cleaved and the amino group of Ser2 was acetylated. I(C)h is folded as a monomeric beta-protein and is devoid of disulfide bonds. It has no inhibitory activity toward CPY, and it does not form a complex with CPY. I(C)h was exclusively expressed in the early log phase, whereas I(C) was expressed in the logarithmic and stationary phase. The intracellular localization of I(C)h was different from that of I(C). These findings provide insights into the physiological functions of I(C)h.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Fukada
authors.forename: Joji
authors.initials: J
authors.lastname: Mima
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nagayama
authors.forename: Michiko
authors.initials: M
authors.lastname: Kato
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ueda
mesh_terms: D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002850:Chromatography, Gel; D002942:Circular Dichroism; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D013439:Sulfhydryl Reagents
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; D013439:Sulfhydryl Reagents; C492432:Tfs1 protein, S cerevisiae; C496670:carboxypeptidase Y inhibitor IC, S cerevisiae