Carboxypeptidase Y stability

• Published in: The Journal of biological chemistry Vol. 266; no. 31; pp. 20818 - 20822
• Main Authors: Lewis, W.S., Schuster, S.M.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 05-11-1991; American Society for Biochemistry and Molecular Biology
• Subjects: Ammonium Sulfate - chemistry; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Carboxypeptidases - chemistry; Carboxypeptidases - metabolism; Detergents - chemistry; effects on; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Hydrolases; Hydrolysis; In Vitro Techniques; Peptidyl Transferases - chemistry; Peptidyl Transferases - metabolism; Protein Denaturation; Solvents - chemistry; Temperature; temperature effects; Time Factors; Organic solvent; Temperature; Enzymatic activity; Enzyme; Enzymatic digestion; pH; Carboxypeptidase
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)54782-7

The stability of carboxypeptidase Y under different reaction conditions and in the presence various cosolvents was investigated. Loss of both hydrolysis and transpeptidation activities was monitored. Incubation of the enzyme at high temperatures or high pH resulted in the loss of both activities at the same rate. Addition of ammonium sulfate resulted in loss of transpeptidation activity but not hydrolysis activity. Addition of some organic solvents or Triton X-100 to the incubation mixture resulted in loss of both activities with transpeptidation being lost more rapidly than hydrolysis activity, while other organic solvents were observed to eliminate both activities entirely. Incubation of the enzyme in the presence of sodium dodecyl sulfate resulted in a decrease in both activities but hydrolysis was lost more rapidly than the transpeptidase activity. Implications of the observed preferential loss of activities to the labeling of peptides and proteins is discussed.