Studies on collagen. I. Structure of the collagen group of proteins

Abstract

The paper reports the details of the revised structure of collagen. It is composed of three helical polypeptide chains, each of which has ten residues in three turns of a left-handed helix. The three chains are further wound into a superhelix in the form of interwined coiled coils. The major helix is right-handed and makes one turn in thirty residues. The structure has reasonable hydrogen bonds, two for every three residues. The shree-chain cylindrical rods are stacked together in hexagonal array and stabilised by cross-linkages through hydroxyproline side-groups. In trying to fit these in the lattice, a slight uncoiling of the major helix is required, resulting in a repeat of 618 A along the fibre axis. The proposed structure is in good agreement with the infra-red and X-ray data and also fits in broadly with the amino-acid composition and other properties of collagen.