Purification and Characterization of Fibronectin from the Plasma of Carp

Abstract

Fibronectm in the plasma of carp Cyprinus carpio (CpFN)was purified to homogeneity on SDS-PAGE by sequential column chromatographies on thermally denatured carp sking collagen (carp gelatin)-Sepharose 4B, arginine-Sepharose 4B and Sepharose CL-4B.
The compositions of carbohydrate and amino acid of the purified CpFN were quite similar to those of bovine plasma fibronectin (BpFN) purified by the procedures similar to those for the CpFN. The CpFN reduced with 2-mercaptoethanol showed two bands, 215 kDa and 220 kDa, on SDS-PAGE, and the unreduced CpFN showed a single band of about 440 kDa, suggesting that the CpFN was a disulfide-bonded dimer of two nonidentical subunit polypeptides, which were slightly smaller than those of the BpFN. The CpFN had some fragments resistant to the diges-tion with thermolysin, trypsin, elastase and subtilisine, whose patterns on SDS-PAGE showed distinct differences from those of the BpFN.