Glycosylated molecular variants of C-reactive proteins from the major carp Catla catla in fresh and polluted aquatic environments.

Elevated level of pollutant specific glycosylated molecular variants of C-reactive protein have been purified to electrophoretic homogeneity from the sera of major carp, Catla catla confined in freshwater (CRP(N)) and water polluted with nonlethal doses of cadmium (CRP(Cd)), mercury (CRP(Hg)), phenol (CRP(Ph)) and hexachlorocyclohexane (CRP(Hex)). These CRPs differ amongst themselves in electrophoretic mobility, and in their carbohydrate content ranging from 20-50%. CRPs interact with pneumococcal C-polysaccharide (CPS) showing different binding constants. Both phosphorylcholine (PC) and calcium are indispensable for binding. Studies on amino acid compositions, electrophoretic analysis, isoelectric focusing, binding to PC & CPS and secondary structures of the purified CRPs indicate, that, they differ from each other. However, they share the common properties of a CRP, including pentraxin structure revealed by electron microscopy. Taken together, our results provide a new structural insight regarding the connection between the presence of unique molecular variants and probably the toxicity therein combated.