Characterization of C-reactive protein from the eggs of the marine teleost, cyclopterus lumpus L.

Abstract

Further evidence is presented for the existence in teleost fish of proteins homologous with mammalian C-reactive protein. The amino acid composition is given for a C-reactive protein isolated from the eggs of a marine teleost, Cyclopterus lumpus, by extraction with lecithin in the presence of Ca²⁺, followed by electrofocusing. A molecular weight of 150000 was calculated from gel filtration and electrophoresis at different polyacrylamide gel concentrations, while the $\text{s}{}_{\mathrm{<mtext>20,</mtext><mtext>w</mtext>}}$ was 7.4 S. The 1.5-S subunits had an apparent $\text{M}{}_{\mathrm{<mtext>r</mtext>}}$ of 20 000 by SDS-polyacrylamide gel electrophoresis and 21 000 by computer analysis based on amino acid composition. Comparison is made with the physicochemical properties of mammalian C-reactive protein.