Identification of an "alcohol dehydrogenase-activating" protease in grass carp hepatopancreas as a chymotrypsin.
Previous investigation [Tsui et al. (1996) Biochim. Biophys. Acta 1269: 41-46] showed that two active forms of alcohol dehydrogenase can be purified from grass carp. The use of a protease inhibitor and the results of SDS-PAGE analysis of the enzymes suggest that one form (ADH-C) is a proteolytic product of the other (ADH-I). In this study, the protease responsible for the cleavage was purified. The cleavage enzyme had a subunit molecular weight of 28 kDa. An inhibitor study identified it as a serine protease. It exhibited a strong chymotrypsin activity in both esterase and amidase assays with a pH optimum in the range 7.5-8.5. The purified chymotrypsin also cleaved the intact grass carp ADH-I into the two-fragment ADH-C, with an accompanying increase in enzyme activity. A similar effect was not found using horse liver alcohol dehydrogenase.
Lau
K K
KK
Department of Biochemistry, Chinese University of Hong Kong, Shatin, N. T., Hong Kong.
Chan
E Y
EY
Fong
W P
WP
D000426:Alcohol Dehydrogenase / Q000378:metabolism*; D000818:Animals; D002347:Carps / Q000378:metabolism*; D002918:Chymotrypsin / Q000302:isolation & purification* / Q000378:metabolism*; D010450:Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism*; D004789:Enzyme Activation; D000431:Ethanol / Q000378:metabolism; D006736:Horses; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D010179:Pancreas / Q000201:enzymology*; D011480:Protease Inhibitors / Q000494:pharmacology
D011480:Protease Inhibitors; D000431:Ethanol; D000426:Alcohol Dehydrogenase; D010450:Endopeptidases; D002918:Chymotrypsin