エラストイジンに関する研究-IV

Abstract

1) About 23% of the elastoidin is digested by pepsin to small peptides permeable to dialyzing membrane. The dialysable peptides, consisting of the non-collagenous protein (about 20% of the elastoidin by weight) and the probable terminal region of the collagen molecule in elastoidin, have a characteristic amino acid composition, the remarkable amounts of tyrosine (29.1%) being one of the most unique characteristics of the non-collagenous protein. 2) Small amounts of hexose and hexosamine were present in the dialysable peptides, but most of these compounds found in the whole elastoidin fiber remained with the collagen fraction (PSE). 3) Although 3-chlorotyrosine could not be detected, four tyrosine derivatives in addition to tyrosine are found in hydrolysate of the dialysable peptides by paper chromatography. These results show that the peroxide linkages formed by oxidation of two tyrosine residues are not involved in the elastoidin, and the tyrosine derivatives derived from the non-collagenous protein are probably related to unusual cross linkages in elastoidin. 4) After successive treatment of the native elastoidin with pepsin, p-components appearing in the denatured state of the PSE were converted into a-components. This seems to indicate that the cross linkages in the PSE were situated in the terminal regions of the PSE. The authors wish to thank Dr. M. SUYAMA, Ass. Prof. of Tokyo University of Fisheries for amino acid analysis, Mr. K. KANNA, Research Member of Tokai Regional Fisheries Research Laboratory for the ultracentrifugal analysis, and Mr. S. FUTAMI for his technical assistance.