Chemical and physical properties of the carboxypeptidase Y-inhibitor from Baker's yeast.
The purification as well as some characteristics of the carboxypeptidase Y-inhibitor from baker's yeast have been described in a previous report (Matern, H., Hoffmann, M. and Holzer, H. (1974) Proc. Natl. Acad. Sci. U.S. 71, 4874-4878). In this paper, chemical and physical properties of the purified inhibitor are presented. The molecular weight was estimated at 23 400--24 000 and appears to be a monomeric unit. Amino acid analysis and carbohydrate studies are given, showing the existence of three disulfide bonds and one sulfhydryl group per molecule and the absence of carbohydrate residues. The N-terminal amino acid is blocked by an acetyl group. The C-terminal amino acid is lysine. The isoelectric point (pI) is 6.6 and the inhibitor-enzyme complex is stable (at 25 degrees C) betwen pH 5 and 9. The apparent Ki value was calculated as 2.5.10(-9)M.
D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002268:Carboxypeptidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae; D013438:Sulfhydryl Compounds / Q000032:analysis
D000596:Amino Acids; D002241:Carbohydrates; D004791:Enzyme Inhibitors; D013438:Sulfhydryl Compounds; D002268:Carboxypeptidases