title: Cross-link analysis of the C-telopeptide domain from type III collagen.
abstract: Several peptides were isolated from tryptic digests of insoluble calf aorta matrix by chromatography. Reductive pyridylethylation of a tryptic 15 kDa pool released fragments deriving from the C-terminus of type III collagen. A 50-residue peptide Tc(III) was shown by sequence analysis to be the C-terminal peptide from the alpha 1(III)-chain, containing a helical and non-helical region of equal sizes. The peptide was further digested with collagenase to give Colc(III), comprising the complete C-terminal non-helical region of alpha 1(III) including a hydroxylysine in position 16c. The peptide Tc(III) x TN(III) was isolated, demonstrating covalent cross-linking between the C-terminal non-helical region of one type III molecule and the N-terminal helical cross-linking region of another. Its digestion with cyanogen bromide yielded the small fragments alpha 1(III)CB3B* and alpha 1(III)CB3C, confirming TN(III) as an N-terminal helical crosslink site. Sequence analysis of both Tc(III) x TN(III) and its collagenase-derived cross-linked peptide Colc(III) x TN(III) established the 4D-staggered alignment of adjacent collagen III molecules. The cross-link structure of both peptides was mainly dihydroxylysinonorleucine with a small amount of hydroxylysinonorleucine, indicating that the lysine residues involved in formation of the cross-links are both hydroxylated. No pyridinoline or histidinohydroxylysinonorleucine cross-links were found within the non-reduced C-telopeptide region of type III collagen.
authors.affiliation: Institut für Arterioskleroseforschung, Universität Münster, Federal Republic of Germany.
authors.forename: W
authors.initials: W
authors.lastname: Henkel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000737:chemistry; D001483:Base Sequence; D001894:Borohydrides; D002417:Cattle; D002850:Chromatography, Gel; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004220:Disulfides; D046911:Macromolecular Substances; D008961:Models, Structural; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D014357:Trypsin
chemical_list: D001894:Borohydrides; D003432:Cross-Linking Reagents; D004220:Disulfides; D046911:Macromolecular Substances; D010446:Peptide Fragments; C025364:sodium borohydride; D003094:Collagen; D014357:Trypsin