Analyses of lysine aldehyde cross-linking in collagen reveal that the mature cross-link histidinohydroxylysinonorleucine is an artifact.

ABSTRACT: Lysyl oxidase-generated intermolecular cross-links are essential for the tensile strength of collagen fibrils. Two cross-linking pathways can be defined, one based on telopeptide lysine aldehydes and another on telopeptide hydroxylysine aldehydes. Since the 1970s it has been accepted that the mature cross-linking structures on the lysine aldehyde pathway, which dominates in skin and cornea, incorporate histidine residues. Here, using a range of MS-based methods, we re-examined this conclusion and found that telopeptide aldol dimerization is the primary mechanism for stable cross-link formation. The C-telopeptide aldol dimers formed labile addition products with glucosylgalactosyl hydroxylysine at α1(I)K87 in adjacent collagen molecules that resisted borohydride reduction and after acid hyd

SUBMITTER: Eyre DR 

PROVIDER: S-EPMC6484114 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature