title: Collagenase digestion demonstrates carboxy-terminal crosslinking in acid-soluble collagen.
abstract: Among the products of the collagenase cleavage of Type I acid-soluble collagen from calf and rabbit tendons, there can be found fragments with the lengths of half alpha-chains. Because purified collagenase cleaves the alpha-chains three-quarters of the length from the amino-terminus, the presence of half-length chains is evidence for the occurrence of crosslinks between two carboxy-terminal, quarter-length fragments, The collagen preparations were reduced with [3H]borohydride, the collagenase-cleaved fragments were separated by gel electrophoresis, and their 3H-labeled crosslink derivatives were analyzed. The major labeled components in the half-length chains were the reduced aldol condensation product and hydroxylysinonorleucine. These experiments demonstrate that the carboxy-terminal telopeptides in monomer-enriched collagen samples form aldol crosslinks which are probably intramolecular, but some intermolecular aldol and aldimine crosslinks may also be formed.
mesh_terms: D000818:Animals; D001894:Borohydrides; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D003094:Collagen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D003012:Microbial Collagenase / Q000378:metabolism*; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000032:analysis*; D011817:Rabbits; D012995:Solubility; D013402:Sugar Alcohols; D013710:Tendons / Q000032:analysis
chemical_list: D001894:Borohydrides; D010446:Peptide Fragments; D013402:Sugar Alcohols; C025364:sodium borohydride; D003094:Collagen; D003012:Microbial Collagenase