The midgut endopeptidases of the honey bee ( Apis mellifica): Comparison of the enzymes in different ontogenetic stages

Abstract

Endopeptidases from the midguts of larval and adult honey bee workers were purified. The chymotryptic proteases B III and B IV were present in both developmental stages, whereas the tryptic protease A was only found in adult workers. From larval workers, however, an anodic Bz-Arg-Nan splitting enzyme could be purified. As shown by immunological techniques, the proteases B of adult and larval workers were identical. Protease A or cross-reacting material for precursor molecules of this enzyme could not be detected in the larval stage. Protease A and the larval Bz-Arg-Nan hydrolysing enzyme showed no immunological relationship. During the ontogeny of the honey bee worker the proteolytic activity is decreased. During the replacement of the larval midgut cells the Bz-Arg-Nan activity increases. Protease A is firstly synthetised by the adult worker bee after emerging from its cell.