The Macromolecular Organization of Dentine Matrix Collagen. I. Characterization of Dentine Collagen

Bovine dentine matrix collagen and corium collagen were isolated and purified. These hardand soft-tissue collagens were then compared in terms of amino acid composition, hexose and hexosamine content, and reactivity of the ϵ-amino groups of lysine and hydroxy lysine. The principal differences were that the dentine matrix collagen was found to contain phosphorus (at least partially in the form of phosphate bound to serine as phosphoserine) and that the ϵ-amino groups of lysine were more readily reactive with fluorodinitrobenzene than were similar groups in the corium collagen. Comparative swelling and solubility studies show that the dentine matrix collagen is a highly cross-linked system. Consideration of the potential cross-linking mechanisms leads to the tentative conclusion that the enhanced stabilization of the dentine matrix collagen stems from the presence of phosphate-mediated di- or triester intermolecular cross-linkages.