[Influence of ligands characteristic of selective binding on DNA helix-coil transition. II. Expansion of DNA melting curves into constitutents. Inverse problem of melting of the block heterogeneity DNA. Determination of the content ratio of binding centers to DNA degree of helicity].

The method for determination of distribution density function of base pairs at blocks with different GC-content in DNA (p(kappa)) was developed. For this purpose a differential melting curve is expanded into constituents possessing Gaussian form. Dependences of the content ratio of DNA ligand binding centres of different kinds at helical and coil regions were expressed through p(kappa). These dependences are used for calculation of the ligand influence on a helix--coil transition. It is shown that in spite of incorrectness of p(kappa) determination, the problem of determining content ratio of different kind binding centres expressed through p(kappa) is a correct problem.