アワビコラーゲンの二,三の性質について

抄録

In order to investigate the shellfish collagen, the body of abalone, Haliotis discus, was isolated and characterized with respect to the amino acid composition and some physical properties. The collagen content of the body was about 20% and was rich in foot part which plays the role of locomotive organ. As most of the collagen was insoluble in neutral salts or dilute acids, the insoluble collagen was solubilized by pepsin. The pepsin solubilized collagen (PSC) was precipitated by addition of NaCl to a final concentration of 5% and redissolved in 0.01 N HCl.
The values of intrinsic viscosity and optical rotation of the PSC were similar to those of vertebrate collagens, such as mammalian or fish skin collagens, but distinct differences were found in the amino acid composition. The PSC was rich in acidic amino acids, amide, hydroxylysine, and tyrosine, but poor in glycine, alanine, and histidine. The values of denaturation temperature (Td: 22.5°C at pH 2) and total imino acids content (181.3 residue/1000) showed a good agreement with usual collagens with respect to the relationship between these two values. One of the most characteristics is a further hydroxylation of lysine. The content of hydroxylysine was larger than that of lysine, thus the ratio of lysine to hydroxylysine was about 0.6, comparing with 3-5 for vertebrate collagens. Moreover, the PSC contained a small amount of cystine (2.8 residues/1000) and a considerable amount of hexose (2.2%). These characteristics in amino acid composition corresponded with the finding in other invertebrate collagens, Metridium and Thyone, reported by Piez et al.
From these results, it is assumed that the collagen from the body of abalone is similar to vertebrate collagens in its molecular structure, but not in amino acid composition.