Abstract: | The first stage of protein self-organization—the formation of a fluctuating secondary structure in the unfolded protein chain—is considered. The stereochemical theory is presented enabling one to calculate helix-coil and β-structure-coil equilibrium constants. It is shown that the most probable localization of fluctuating α- and β-structure in the unfolded protein chain corresponds to the native localization of these structures. The formation of large α- and β-structural blocks is observed, each of them including several native α-helices or β-strands. |