[Possibility of wide-angle neutron scattering in the study of proteins and nucleic acids in solutions]

A method is proposed for calculating wide-angle neutron scattering curves of biopolymers at any fraction of heavy water (D2O) in solution. The method permits to accurately take into account the phenomenon of deuteroexchange. By this method neutron scattering curves of proteins and DNA have been calculated. The calculations have shown that at optimal fractions of D2O in solution the profiles of neutron scattering curves and their sensitivity to conformational rearrangements in protein molecules turned out to differ very little from those of corresponding X-ray curves. Thus the neutron scattering curves do not contain any additional information (as compared with those contained in X-ray scattering curves) on the structure of proteins in solution. On the contrary, neutron and X-ray scattering curves of DNA differ significantly at all fractions of D2O in solution and therefore the methods of wide-angle neutron and X-ray scattering could become mutually complementary in studying the structure of nucleic acids in solution.