A theory of protein molecule self-organization: IV. Helical and irregular local structures of unfolded protein chains

Abstract

A theory of formation of α-helices and irregular local structures in unfolded protein chains is presented. It has been shown that practically all the native α-helices pre-exist in the unfolded chain as fluctuating embryos though not all the α-helices pre-existing in the unfolded chain are contained in native proteins. It has also been shown that the overwhelming majority of the β-bends and other irregular local structures do not pre-exist in the unfolded chain. From this a conclusion has been drawn that λ-helices can initiate self-organization of the tertiary structure serving as blocks for its assembling while the irregular local structures cannot initiate protein folding.