Expression and characterization of honeybee, Apis mellifera , larva chymotrypsin-like protease

Previously, we found three enzyme fractions containing activities for the hydrolysis of royal jelly proteins from honeybee queen larvae. In this study, we identified a honeybee chymotrypsin-like protease (HCLPase) by LC-MS/MS and expressed it as a recombinant protein in Escherichia coli . The protease had an estimated molecular weight of around 26 kDa and showed high specificity for succinyl-Ala-Ala-Pro-Phe p -nitroanilide as a proteolytic substrate. Furthermore, the protease had an optimal pH of 9, and the activity was markedly inhibited by phenylmethylsulfonyl fluoride but not tosyl phenylalanyl chloromethyl ketone, both of which are irreversible inhibitors of chymotrypsin-like serine proteases. These results suggested that this recombinant protease, HCLPase, was a chymotrypsin-like serine protease with different characteristics from mammalian chymotrypsin.