Possible mechanism of non-monotone behavior of helix-coil transition temperature in two-component solvent

Within the frameworks of generalized model of polypeptide chain (GMPC) the concentrational behavior of helix-coil transition temperature of biopolymer in two-component solvent was observed on the simplest models. It is shown that if the solvent and the ligand interact with the biopolymer at different binding sites, and even if both components influence the helical state in the same way, the model allows one to obtain the non-monotone character of the melting temperature behavior of biopolymer depending on the ligand concentration. It is shown that changes in the regime of helical state stability is not always related with the competition of stabilizing and destabilizing interactions of blend components but can be the result of the cumulative effect of both components.