IDENTIFICATION OF 2 INTERCHAIN CROSSLINKS OF BONE AND DENTINE COLLAGEN

Bone and dentine collagens are virtually insoluble in the solvents employed to extract native tropocollagen from soft tissue collagens. The decrease in the ease of extraction of the tropocollagen is generally considered to be due to an increase in the presence of crosslinked components (see Piez, 1968; Bailey, 1968a for reviews). Bone and dentine collagen must therefore be extensively intermolecularly crosslinked, but the chemistry of the crosslink is unknown. Glimcher and his co-workers (1965a; b) suggested that non-covalent bonds are involved in the stabilization of bone. However a recent report by Miller et al. (1967) clearly demonstrated the presence of stable covalent inter-chain crosslinks in the denatured guanidine-HCl extract from bone. Veis and Schlueter (1964) similarly concluded that dentine was extensively crosslinked by stable covalent bonds, and proposed phosphatemediated ester bonds in addition to a system of periodate sensitive bonds. Our recent studies on the crosslinks of soft tissue collagens have demonstrated the presence of both labile and stable intermolecular crosslinks (Bailey, 1968b; Bailey and Peach, 1968). The present communication describes the isolation and identification of two covalent inter-chain crosslinks stabilizing bone and dentine. © 1969.