SUBUNIT COMPOSITION OF 2 DISTINCT TYPES OF COLLAGEN IN THE MUSCLE OF THE SQUID TODARODES-PACIFICUS

Two genetically distinct alpha components were isolated from each of the major and minor collagens, Type SQ-I and SQ-II collagens, from the mantle muscle of squid by phosphocellulose column chromatography, called alpha1(SQ-I) and alpha2(SQ-I), alpha1(SQ-II) and alpha2(SQ-II), respectively. The alpha1(SQ-I) and alpha1(SQ-II) components were shown to be genetically distinct from each other by peptide mapping and amino acid analysis. On the other hand, the alpha2(SQ-I) and alpha2(SQ-II) components, which migrated at almost the same position on SDS-PAGE, were similar in peptide map and amino acid composition. However, slight differences were observed in both features, suggesting genetic differences. From the results, Type SQ-I and SQ-II collagens were demonstrated to be heterotrimers [alpha1(SQ-I)]2alpha2(SQ-I) and [alpha1(SQ-II)]2alpha2(SQ-II), respectively.