EFFECT OF ELECTROELASTIC ANISOTROPY OF DNA-LIKE MOLECULES ON THEIR TERTIARY STRUCTURE

Under certain conditions, mechanical forces can cause an anisotropic m olecule like DNA to assume a toroidal spatial structure. A simple mode l describing such a behavior is suggested. The model incorporates anis otropic elastic energy and external electrical forces. The steady-stat e structures formed by a macromolecule have been studied numerically u sing this model. There exist ranges of model parameters, namely, the a nisotropy of the elastic tensor, magnitude and orientation of forces, and modulation periods, where molecules have toroidal, spherical, or e xtended structures. Estimates of parameters characteristic of these st ructures are consistent with experimental data. In particular, the tor oidal structure dimension corresponds to experimental dimensions of to roidal globules produced as a result of so-called PSI condensation of DNA molecules. (C) 1997 American Institute of Physics. [S1063-7761(97) 01612-0].