title: Mutated intramolecular chaperones generate high-activity isomers of mature enzymes.
abstract: The propeptide of carboxypeptidase Y precursor (proCPY) acts as an intramolecular chaperone that ensures the correct folding of the mature CPY (mCPY). Here, to further characterize the folding mechanism mediated by the propeptide, folding analysis was performed using a yeast molecular display system. CPYs with mutated propeptides were successfully displayed on yeast cell surface, and the mature enzymes were purified by the selective cleavage of mutated propeptides. Measurement of the activity and kinetics of the displayed CPYs indicated that the propeptide mutation altered the catalytic efficiency of mCPY. Although the mature region of the wild-type and mutant CPYs had identical amino acid sequences, the mCPYs from the mutant proCPYs had higher catalytic efficiency than the wild-type. These results indicate that proteins with identical amino acid sequence can fold into isomeric proteins with conformational microchanges through mutated intramolecular chaperones.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nagayama
authors.forename: Haruko
authors.initials: H
authors.lastname: Maeda
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ueda
mesh_terms: D002384:Catalysis; D043402:Cathepsin A / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004789:Enzyme Activation / Q000235:genetics; D004792:Enzyme Precursors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D017510:Protein Folding; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: D004792:Enzyme Precursors; D007527:Isoenzymes; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; D043402:Cathepsin A; C499283:PRC1 protein, S cerevisiae