title: Biochemical characterization of guanidinium chloride-soluble dentine collagen from lathyritic-rat incisors.
abstract: alpha- and beta-Chains were isolated by sequential ion-exchange and gel-filtration chromatography of guanidinium chloride-soluble dentine collagen obtained from Tris/NaCl-extracted EDTA-demineralized lathyritic-rat incisors. The alpha-chains were identified as alpha 1 I and alpha 2 by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and amino acid analysis of the intact chains and their CNBr peptides. The dentine alpha-chains exhibited higher lysine hydroxylation and phosphate content, but lower hydroxylysine glycosylation, than alpha-chains from skin. Increased lysine hydroxylation was observed in the helical sequences. The alpha 1 I/alpha 2 ratio was approx. 3:1, and was presumably due to the presence of (alpha 1 I)3 molecules along with (alpha 1 I)2 alpha 2 molecules as shown recently for neutral-salt-soluble dentine collagen [Wohllebe & Carmichael (1978) Eur. J. Biochem. 92, 183--188]. In the borohydride-reduced beta 11- and beta 12-chains from guanidinium chloride-soluble dentine collagen, the reduced cross-links hydroxylysinohydroxynorleucine and hydroxylysinonorleucine were present. A higher proportion of hydroxylysinonorleucine in the reduced beta 12-chain probably reflects differences in extent of hydroxylation of specific lysine residues of the alpha 1 I- and alpha 2-chains.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002852:Chromatography, Ion Exchange; D003094:Collagen / Q000302:isolation & purification; D003432:Cross-Linking Reagents; D003804:Dentin / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006027:Glycosides / Q000032:analysis; D006146:Guanidines; D006901:Hydroxylysine / Q000031:analogs & derivatives / Q000032:analysis; D007180:Incisor; D007842:Lathyrism / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D051381:Rats
chemical_list: D000596:Amino Acids; D003432:Cross-Linking Reagents; D006027:Glycosides; D006146:Guanidines; D010446:Peptide Fragments; D010710:Phosphates; D006901:Hydroxylysine; D003094:Collagen