PROTEOGLYCANS FROM ADULT WORMS OF SCHISTOSOMA-HAEMATOBIUM

Different types of proteoglycans (PGs) from adultworms of Schistosoma haematobium, were sequentially extracted using chaotropic agents under associative conditions (0.5 M GnCl), dissociative conditions (4 M GnC l) and detergents (Triton X-100 and SDS). The extracts were designated F1, F2, F3 and F4, respectively. The highest amount of uronic acid an d carbohydrate was detected in the associative extract (F1) while the highest amount of protein was detected in the SDS extract (F4). Agaros e polyacrylamide gel electrophoresis (A-PAGE) indicated the presence o f a different PG in each extract with different electrophoretic mobili ties. Agarose gel electrophoresis of glycosaminoglycan (GAG) separated from GnCl, associative and dissociative extracts, and the residue sug gested the presence of dermatan sulphate in the two extracts and the r esidue, in addition to a GAG-like material found in the associative ex tract only. This glycosaminoglycan showed resistance to digestion with all mucopolysaccharidases and nitrous acid treatment. Gel filtration chromatography of associative extract on Sepharose CL-6B indicated the presence of three main uronic acid peaks (P1, P2 and P3). Chondroitin sulphate was the main GAG that could be detected in peak one (P1). Pe ak two (P2) contains carbohydrate and uronic acid but has no protein o r absorbance at 280 nm. P2 has two types of GAGs: dermatan sulphate an d a GAG-like material. The role of this PG in helping the adult schist osomes in evading immobilization by the host blood clotting cascade is discussed. Antibodies to peak one and peak two were detected in hamst er sera infected with S. haematobium and S. mansoni using the ELISA te st. The specificity of peak two was found to be evident in its low cro ss-reactivity (18.9%) when confronted with S. mansoni infected sera.