Studies on chymotrypsin-like catalysis by synthetic peptides.
The synthetic peptide Chymohelizyme-1 (CHZ-1) exhibits esterase activity against carbobenzoxytyrosine p-nitrophenyl ester (ZTONP), carbobenzoxyalanine p-nitrophenyl ester (ZAONP), and t-butyloxy-carbonyltyrosine p-nitrophenyl ester (BocTONP). However, earlier reports of catalytic activity against less labile esters and amides have proven to be incorrect. The major reason for the errors appears to have been the omission of certain controls in the previous work. Although the catalytic triad does not appear to be functioning as designed, the catalytic activity of CHZ-1 does depend on the integrity of its primary structure. The pH dependence of hydrolysis of ZTONP points to general-base catalysis, whereas a preference for hydrophobic substrates suggest that the structure of CHZ-1 is performing some other role in assisting catalysis.
Corey
M J
MJ
Department of Biochemistry, University of Colorado School of Medicine, Denver 80262.
Hallakova
E
E
Pugh
K
K
Stewart
J M
JM
D000409:Alanine / Q000031:analogs & derivatives / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000378:metabolism; D000595:Amino Acid Sequence; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000138:chemical synthesis / Q000378:metabolism*; D004950:Esterases / Q000138:chemical synthesis / Q000378:metabolism*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism*; D013379:Substrate Specificity; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D010455:Peptides; C088727:N-carbobenzoxyalanine 4-nitrophenyl ester; C089568:t-butyloxycarbonyltyrosine 4-nitrophenyl ester; C006716:benzoyltyrosine ethyl ester; C028121:N-benzyloxycarbonyltyrosine-4-nitrophenyl ester; D014443:Tyrosine; C007651:ethyl N-alpha-acetyl-tyrosinate; D000426:Alcohol Dehydrogenase; D004950:Esterases; C089569:chymohelizyme 1; D002918:Chymotrypsin; D000409:Alanine