Collagen structure with a new net of hydrogen bonds

A conformational variability of the collagen triple helix was studied with the methods of molecular mechanics. The Rich-Crick model with one hydrogen bond per tripeptide fragment or the model with two hydrogen bonds per tripe ptide fragment were used for tripeptides forming the primary structure of t he protein. Imino acid and amino acid residues were located in the second p osition of the tripeptide fragments in the first and second cases, respecti vely. Conformations on domain boundaries, which had alternating structures with one and two hydrogen bonds per tripeptide, were particularly studied. Essentially all types of collagen backbone composed of amino acid residues most frequently occurring in this protein were considered. A new model was suggested that combined elements of the Rich-Crick model and our new approa ch. This was shown to be stereochemically valid, energetically advantageous , and consistent with the experimental data. It was conclusively demonstrat ed that the primary structure of collagen determines its tertiary structure .