Identification of GTP-binding proteins in Fasciola hepatica and Schistosoma mansoni by immunoblotting

Abstract

Both the liver fluke Fasciola hepatica and the blood fluke Schistosoma mansoni have GTP-binding proteins which are part of the trans-membrane signalling system. These proteins require GTP in order to interact with the catalytic subunit of adenylate cyclase. The technique of immunoblotting was used in order to distinguish the GTP-binding proteins G s, G i, and G o. Immunoblotting was carried out using antisera prepared against peptides deduced from bovine cDNA clones specific for α or β subunits of known G proteins. A 41-kDa G sα has been identified in S. mansoni and a 42.5-kDa G sα in F. hepatica. A 41-kDa G oα was found in both parasites. A 36-kDa G β was identified in both parasites using antiserum made against bovine transducin.