PURIFICATION AND CHARACTERIZATION OF SURFACE-ASSOCIATED PROTEINS FROMADULT HAEMONCHUS-CONTORTUS

Extrinsic radioiodination experiments have shown that male and female adults of Haemonchus contortus (BPL strain) express a stage-specific s et of surface-associated proteins with apparent molecular mass values of 30, 58, 81, and 143 kDa. A quantitatively different pattern of iodi nated surface proteins is expressed by adults of the PPR strain of H. contortus, whereas the pattern of iodinated proteins expressed by Haem onchus similis is qualitatively distinct (38, 68, and 121 kDa). The 58 -, 81-, and 143-kDa proteins of the BPL strain are glycosylated, where as the 30-kDa protein is not. The binding of wheat germ agglutinin to the surface glycoproteins was inhibited by the trimer of N-acetylgluco samine (N,N,N-triacetylchitotriose) but not by the monosaccharide, ind icating the presence of chitin-like homopolymers. The carbohydrate por tion of the 58-kDa protein is N-linked and accounts for 30% of its app arent mass. Under nonreducing conditions, the 58-kDa glycoprotein form s a high molecular mass polymer that is unable to penetrate a 10% acry lamide gel. The 143- and 81-kDa surface glycoproteins were not hydroly zed by either N- or O-glycanase, indicating unusual modifications to t he saccharide-linkage and rendering it resistant to glycosidase digest ion. The 30-, 58-, and 143-kDa purified surface proteins produced dist inct peptide maps with Staphylococcus aureus V8 protease.