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

Abstract

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.