Intermolecular cross-links in type I collagen
Diagram showing the sites, type and ratio of pyridinoline cross-links in bone type I collagen. Pyridinolines stabilize type I collagen fibrils of human bone at both ends of the molecule. HP is more abundant at the C-telopeptide-helix cross-link site (HP/LP ratio, 6:1) and LP is more abundant at the N-telopeptide-helix site (HP/LP ratio, 2:1) [19].