Thermodynamic substantiation of water‐bridged collagen structure

A solution of the problem of topology of a hydrogen bond net in a triple helix of collagen is suggested on the basis of an analysis of thermodynamic data on denaturation of phylogenetically different collagen [T. V. Burjanadze (1982), Vol. 21, pp. 1489–1501; T. V. Burjanadze, E. I. Tiktopulo, and P. L. Privalov (1987), Dokl. Akad, Nauk. USSR, Vol. 293, pp. 720–724] as well as on the earlier evaluation of the energy of the OH group of the 4−hydroxyproline bond [A. R. Ward and P. Mason (1973), Journal of Molecular Biology , Vol. 29, pp. 431–435]. It is shown that only the water‐bridged collagen structure [G. N. Ramachandran and R. Chandrasekharan (1968), Biopolymers , Vol. 6, pp. 1649–1661: G. N. Ramachandran, M. Bansal, and R. S. Bhatnagar (1973), Biochimica Biophysica Acta , Vol. 322, pp. 166–171: M. Bansal, C. Ramakrishnan, and G. N. Ramachandran (1975), Proceedings of the Indian Academy of Sciences, Vol. 82, pp. 152–164] can explain both the change of thermostability upon proline hydroxylation [J. Rosenbloom, M. Harsch. and S. Jimenez (1973), Archives of Biochemistry and Biophysics , Vol. 158, pp. 478–484] and its phylogenetic change [T. V. Burjanadze (1982)].