Studies on collagen - III. Oriented crystallisation of inorganic salt on collagen
When collagen fibres are treated with acidic and alkaline solutions of inorganic salts, oriented crystallisation of the salts takes place inside the protein fibre. The treated fibres give X-ray diagrams which closely resemble single crystal rotation photographs. A direct relationship has been established between the crystal parameters lying parallel to the fibre axis and the axial repeat of collagen. Oriented crystallisation does not occur in neutral solution. In both acidic and alkaline solutions the orientation improves with swelling. The chemical treatment is found to have little effect on collagen itself in most of the salts.