Purification of C-reactive protein from Channa punctatus (Bloch)

C-reactive protein (CRP) is found to be a normal component of serum of freshwater air-breathing murrel Channa punctatus. Based on the property of binding with C-polysaccharide (CPS) of pneumococcus bacteria in presence of Ca2+, CRP was purified by phosphorylcholine-Sepharose affinity column chromatography. Molecular weight of the intact protein molecule was estimated to be approximately 141,000 by gel filtration. In non-reduced and reduced conditions the molecule showed molecular weight approximately 28,000 and 14,000 respectively in SDS-PAGE. Monospecific antisera was raised against the affinity purified CRP and used as a tool to detect CRP in the hepatic cytosol and egg extract. The level of CRP in the normal serum was estimated to be 220 micrograms/ml.