DO EXCRETORY-SECRETORY PRODUCTS OF ONCHOCERCA-GIBSONI CONTAIN PHOSPHORYLCHOLINE ATTACHED TO O-TYPE GLYCANS

Excretory-secretory products (ES) of adult male Onchocerca gibsoni con tain phosphorylcholine (PC). PC-ES are detected as a smear of M(r) sim ilar to 60-similar to 200 kDa by western blotting employing a monoclon al antibody (mAb) against PC, suggesting that they are glycoproteins. Exposure of PC-ES to N-glycosidase F results in weak and inconsistent loss of binding of the mAb, indicating that unlike the situation with respect to ES of Acanthocheilonema viteae, PC is highly unlikely to be solely attached to N-type glycans. Conversely, treatment of O. gibson i PC-ES with mild alkali, a strategy for removing O-type glycans, abol ishes mAb binding. These results suggest that PC may be attached to O. gibsoni proteins mainly via O-type glycans, and raise the possibility that filarial parasites may vary with respect to their mode of attach ment of PC. The implications of this with respect to the design of inh ibitors of PC attachment for use as anti-filarial drugs, are discussed . Copyright (C) 1996 Australian Society for Parasitology. Published by Elsevier Science Ltd.