Peptidolytic enzymes in different larval stadium of housefly Musca domestica

Four classes of peptidolytic enzymes were described in insects. Many authors have found predominant activity belonging to trypsin-like and chymotrypsin-like activity. By the use specific chromogenic substrates and hemoglobin we have determined enzyme activity in three stages of larval development of housefly. In contrast to above mentioned data we have found, that major part of peptidolytic activity in this insect is of aminopeptidase nature. Other observed peptidolytic activity formed only minority part. Apparently the highest activities to all examined substrates were found in first larval stadium of housefly. Inhibitory studies by class specific inhibitors and influence of metal ions and chelating agent on enzyme activity have shown, that aminopeptidase-like enzymes belong to metalloproteinase group.