STUDIES ON COMPLETE PRIMARY STRUCTURE OF FISH TYPE I PROCOLLAGEN

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 11460096
• Research Category: Grant-in-Aid for Scientific Research (B).
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Fisheries chemistry
• Research Institution: TOKYO UNIVERSITY OF FISHERIES
• Principal Investigator: KIMURA Shigeru TOKYO UNIVERSITY OF FISHERIES, DEPARTMENT OF FISHERIES, PROFESSOR, 水産学部, 教授 (10017056)
• Project Period (FY): 1999 – 2000
• Keywords: FISH / TYPE I COLLAGEN / cDNA / COMPLETE PRIMARY STRUCTURE / AMINO ACID SEQUENCE / PROCOLLAGEN / RAINBOW TROUT

Research Abstract

The major fibrous collagen of vertebrates is type I collagen consisting of two α1 (I) chains and one α2 (I) chain. However. type I collagens from many bonylishes have a unique α chain, α3 (I), and comprise α1 (I) α2 (I) α3 (I) heterotrimers. In this study, the complete primary structure of type I procollagen was determined by using the cDNA library of rainbow trout fibroblasts. The pro α1 (I), pro α2 (I), and pro α3 (I) chains were found to comprise 1449, 1356, and 1458 amino acid residues, respectively, and the main helical-triple domain of each pro α (I) chain had 338 uninterrupted Gly-X-Y triplets having 1014 amino acid residues. Particularly, the pro α3 (I) chain was characterized by the low content of Gly-Pro-Pro triplets and the high content of Gly-Gly doublets. These features seem to reflect the low thermal stability of rainbow trout. type I collagen. The amino acid sequence homology among pro α (I) chains was determined ; pro α3 (I) had 73% and 56% homology to pro α1 (I) and pro α2 (I). respectively. and pro α1 (I) had 58% homology to pro α2 (I). Moreover, the phylogenetic analysis revealed that pro α3 (I) had diverged from pro α1(I). This is the first report of the complete primary structure of fish tape I procollagen and thus is assumed to contribute to much understanding of the function and metabolism of fish type I collagen.