Carboxypeptidase functional characterization

Metabolic Functions. Zinc is essential for the function of many enzymes, either in the active site, ie, as a nondialyzable component, of numerous metahoenzymes or as a dialyzable activator in various other enzyme systems (91,92). WeU-characterized zinc metahoenzymes are the carboxypeptidases A and B, thermolysin, neutral protease, leucine amino peptidase, carbonic anhydrase, alkaline phosphatase, aldolase (yeast), alcohol... 

Shirley, A. M., and Chappie, C., 2003, Biochemical characterization of sinapoylglucose choline sinapoyltransferase, a serine carboxypeptidase-like protein that functions as an acyltransferase in plant secondary metabolism, J. Biol. Chem. 278 19870-19877. 

Figure 6.1 Characterization of impaired prohormone processing in mice lacking functional active carboxypeptidase E (Cpe mice) by peptidomics.

One of the most important discoveries concerning the biological role of zinc occurred in 1940 when Keilin and Mann showed that zinc is an essential compound of erythrocyte carbonic anhydrase, an enzyme cata-lytically involved in the transport of CO2 in blood (6). Following the 70-year interval between the initial recognition of a metabolic zinc deficiency and the characterization of the first zinc metalloenzyme, there was a period of about 15 years before the second zinc enzyme was identified. In 1955, Vallee and Neurath reported that carboxypeptidase A from bovine pancreas contained 1 g-atom Zn per mol of protein and was essential to the function of the enzyme (7). The presence of zinc in carbonic anhydrase and carboxypeptidase A indicated that a primary role of zinc would be to function in zinc metalloenzymes (62). However, it seemed unhkely that disrupting the activity of carboxypeptidase A or carbonic anhydrase would have profound eflFects on growth. 

Normant. E. Martres, M. Schwartz. J. Gros, C. Purification. cDNA cloning, functional expression, and characterization of 26-kDa endogenous mammalian carboxypeptidase inhibitor. Proc. Natl. Acad. Sci. U. S. A. 1995. 92. 12225-12229. 

---