A sulfated chitin inhibits hemagglutination by Theileria sergenti merozoites

Five structurally different polysaccharides were examined for their hemagglutination inhibition activity. A (1 --> 4)-linked homopolysaccharide composed of N-acetyl, 6-O-carboxymethyl glucosamine (CM-chitin) showed no inhibitory activity but a 3,6-O-sulfated derivative of CM chitin (SCM-chitin III) showed potent hemagglutination inhibition activity. A N-sulfated derivative of N-deacetylated CM chitin (SCM-chitosan) however, was not effective. Chondroitin sulfate and dermatan sulfate, both of which consisted of disaccharide repeats of (1 --> 3)-linked uronic acid and galactosamine sugar residues (--> 4GlcAb1/IdoAal --> 3GalNAcb1), did not interfere with the red blood cell (RBC) binding by T. sergenti merozoite. Thus, the sulfated glycoconjugate interaction is presumed to be an important process in the RBC invasion by the Theilerial merozoite. (C) 1999 Elsevier Science Ltd. All rights reserved.