The present state of the theory of strongly charged polyelectrolytes of the DNA type is reviewed. An infinitely long, uniformly charged cylinder immersed in a dielectric continuum is adopted as a model of DNA. Small mobile ions are treated as impermeable spheres. A comparison of the results of rigorous and approximate theoretical approaches to the description of this model shows that the self-consistent-field method, i.e., the Poisson-Boltzmann equation, is a reliable basis for deriving quantitative results. The theory of polyelectrolytes based on a solution of the nonlinear Poisson-Boltzmann equation is used to analyze the role played by electrostatic interactions in conformational changes in DNA. Transitions of two types are considered: a helix-coil transition and a transition between the ordinary right-hand-helix DNA (the B form) and the recently discovered left-hand-helix (the Z form). In the latter case the theory predicts a nonmonotonic behavior of the difference between the free energies of these conformations as a function of the salt concentration. It also predicts the existence of a critical point of a B-Z equilibrium for ionic strengths in the physiological region.
@article{Frank-Kamenetskii:1987,author = {M. D. Frank-Kamenetskii and V. V. Anshelevich and A. V. Lukashin},title = {Polyelectrolyte model of DNA},publisher = {Physics-Uspekhi},year = {1987},journal = {Phys. Usp.},volume = {30},number = {4},pages = {317-330},url = {https://ufn.ru/en/articles/1987/4/b/},doi = {10.1070/PU1987v030n04ABEH002833}}