Chemical studies on the cyanogen bromide peptides of rat skin collagen. Amino acid sequence of alpha 1-CB3

A method for the selective release and, hence, assay of the carbohydrate moieties of collagen

The carbohydrate residues of collagen were selectively released in high yield by nitrosation of the hydroxylysines of the intact collagen or peptides derived from collagen. The carbohydrate residues (Glc-Gal and Gal) released were separated from the modified protein or peptide by gel chromatography and were assayed by gas-liquid chromatography of their trimethylsilyl derivatives. The results agreed closely with those obtained from methanolysis-gas chromatography or from alkaline hydrolysis followed by amino acid analysis of the hydroxylysyl glycosides. With a more sensitive perbenzoylation-high-performance liquid chromatography method and uv detection at 230 nm, the carbohydrates released by nitrosation of submilligram quantities of collagen or peptide could be assayed accurately.

The covalent structure of cartilage collagen. Amino acid sequence of residues 552-661 of bovine alpha1(II) chains

The covalent structure of the first 111 residues from the N-terminus of peptide alpha1(II)-CB10 from bovine nasal-cartilage collagen is presented. This region comprises residues 552-661 of the alpha1(II) chain. The sequence was determined by automated Edman degradation of peptide alpha1(II)-CB10 and of peptides produced by cleavage with trypsin and hydroxylamine. Comparison of this region of the alpha1(II) chain with the homologous segment of the alpha1(I) chain indicated a homology level of 85%, slightly higher than that of 81% reported for the N-terminal region of the alpha1(II) chain (Butler, Miller & Finch (1976) Biochemistry15, 3000-3006). The occurrence of two residues of glycosylated hydroxylysine was established at positions 564 and 603, the first present exclusively as galactosylhydroxylysine and the latter as a mixture of galactosylhydroxylysine and glucosylgalactosylhydroxylysine. Also, two residues at positions 648 and 657 were tentatively identified as glycosylated hydroxylysines. The amino acid sequences adjacent to the hydroxylysine residues so far identified in the alpha1(II) chain were compared with the homologous regions of the alpha1(I) and alpha2 chains, but no obvious prerequisite for hydroxylation could be seen. From comparison with the homologous sequence of the alpha1(I) chain, it appears that the alpha1(II)-chain sequence presented here contains three more amino acids than that reported for the alpha1(I) chain. This triplet would be interposed between residues 63 and 64 of the reported sequence of peptide alpha1(I)-CB7 from calf skin collagen. Data on the purification of the subpeptides and their amino acid compositions have been deposited as Supplementary Publication SUP 50087 (7 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169, 5.

Improved technique for the analysis of amino acids and related compounds on thin layers of cellulose.XI. Direct, visual micro-method for investigating the primary structural sequence of collagen and other proteins

The present paper describes a new variation of the "finger printing" technique for examining the primary structure of proteins. It is based on the production of a reproducible, partial acid hydrolysate consisting of amino acids and small peptides which are separated into compact spots by bi-dimensional thin-layer chromatography. The spots are characterized by ther Rf values and colour reactions with a variety of reagents. The method was initially developed for collagen but has been applied to other proteins, with interesting results. It has developed logically from earlier, systematic studies on amino acids and peptides, and holds promise for the comparative investigation of normal and diseased human collagen.

Biochemical characteristics and biological significance of the genetically-distinct collagens

In recent years it has become evident that genetic polymorphism is dramatically expressed in the structural protein, collagen. Current information on the biochemical properties, biosynthesis, and tissue distribution of Type I, II, and III collagens is summarized with special reference to possible unique functional roles fulfilled by each of these collagens.