GLYCOSYLATION AND ADHESIVENESS DIFFERENTIATE LARVAL CERATITIS-CAPITATA TYROSINASES

Larval Ceratitis capitata phenoloxidases (POs) from hemocytes, serum, integument, and fat body were analyzed. Two types of PO were recorded: the tyrosinase type found in hemocytes, serum, integument, and fat bod y and the laccase type found in integument. Tyrosinase from all larval tissues and integumental laccase as well, showed similarity in molecu lar weight (93 KDa), activation by Escherichia coli al 5 mM Ca2+, and reactivity to antibodies raised against serum tyrosinase. However, the enzymes differed with respect to their glycosylation and adhesiveness . The serum and integumental enzyme forms contain concanavalin A react ing material, whereas hemocyte and integumental tyrosinase(si are adhe sive. These differences in enzyme forms, although not influencing thei r substrate specificity, seem to give advantages to performing their f unction, i.e., the adhesive enzyme form facilitates the adherence to E . coli cell wall and hemocyte surface (unpublished data) while the gly cosylated form facilitated the secretion into serum. (C) 1994 Wiley-Li ss, Inc.