Amino-terminal location of pyridinoline in dentin collagen.
Cross-linking is believed to be one of the major factors that characterize the calcifiability of dentin and bone collagens. Dehydro-dihydroxylysinonorleucine and pyridinoline which constitute the principal cross-links of dentin collagen have so far been located only in the carboxy terminal telopeptide of the molecules [alpha 1(I)-chain 87 x alpha 1(I)-chain 16C]. This situation suggested that the amino terminal telopeptide portion might be "open" without intermolecular cross-linking in hard tissue collagen fibrils. However, the present study provided evidence that pyridinoline is also located in amino-terminal telopeptides (alpha 1-chain 9N or alpha 2-chain 5N) and alpha 1-chain 930. Bovine dentin collagen was digested with trypsin followed by heating at 60 degrees C before and after the digestion. This method gave complete trypsin peptides of dentin collagen. Fluorescent pyridinoline peptides with a smaller molecular size were isolated by Sephadex G-50 superfine, DEAE-cellulose and reverse-phase HPLC. Automatic Edman analysis of several isolated peptides revealed the five-residue sequence, Gly-Ile-X-Gly-His-Arg, the only assignment of which was alpha 1-chain 928-933. The above evidence together with the amino acid compositions of the peptides led to the conclusion that pyridinoline is located not only in the carboxy-terminal but also in the amino-terminal telopeptide in dentin collagen.
Kuboki
Y
Y
Department of Biochemistry, School of Dentistry, Hokkaido University, Sapporo, Japan.
Okuguchi
M
M
Takita
H
H
Kimura
M
M
Tsuzaki
M
M
Takakura
A
A
Tsunazawa
S
S
Sakiyama
F
F
Hirano
H
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism*; D003804:Dentin / Q000378:metabolism*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D014357:Trypsin
D000596:Amino Acids; C015484:pyridinoline; D003094:Collagen; D014357:Trypsin