Backbone Dynamics of Triple-helical Collagen-like Structure.

Some details of the backbone dynamics in the collagen-like triple helix is discussed and the role of backbone dynamics in functioning collagen proteins is illustrated. On a series of oligotripeptides synthetic analogs of collagen formation of high-frequency vibrational backbone dynamics and low-frequency nonlinear backbone dynamics upon stepwise elongation of peptide chain have been described using infrared spectroscopy and hydrogen-exchange method. In the fully completed triple helix the level of high-frequency backbone dynamics is regulated firstly by contact interactions of adjacent atoms and chemical bounded groups, while the level of low-frequency large-amplitude backbone dynamics depends mainly on cooperative interactions attributed by conjugation of interpeptide hydrogen bonds. In native collagens the nonlinear large-amplitude dynamics following by non-denaturational micro-unfolding of the triple-helical structure appears to be under the natural selection control delivering an optimal condition for formation, functioning and utilization of collagen fibrils.