A special attention will be given to the investigation of biological adaptation to 2H2O allowing cells to synthesize a deuterated forms of macromolecules (particulary interest have DNA and short-chain individual proteins both with well known amino acid sequence and conformation) with a certain structure allowing their functioning in 2H2O environment.

Firstly, in this connection it would be very interesting to know, how the structure of fully deuterated macromolecules could be changed neganively or positively in a course of biological adaptation to 2H2O requiring the presence of high concentrations of 2H2O in growth media.

Secondly, if a cell will be growing on media containing the stepwise increasing concentrations of 2H2O, for example starting up from zero up to 100% (v/v) 2H2O, will the changes in the structure of [U -2H]labeled macromolecules to be corresponding to the 2H2O content in media and what is a limit concentration of 2H2O when the macromolecular structure keeps a stable constancy and how this fact corresponds with a limit of biological resistance to 2H2O? For answers to these questions a number of modern consideration at the levels of the structure (primary, secondary, tertiary) and conformation of [U -2H]labeled DNA and individual proteins with using the methods of a special sequencing and modifications of deuterated macromolecules combined together with gel electrophoresis method as well as such powerful methods as NMR-spectroscopy to which will be taken a most part of proposed research, X-ray diffraction, IR-, laserand CD-spectroscopy will be further involved. An investigation will necessary mainly into the structure of [U -2H]labeled macromolecules in order to find at what level of macromolecular hierarchy a substitution of hydrogen atoms with deuterium ensued the consequence on the differences in the structure and the conformation of macromolecules and, therefore, the functional properties of the macromolecules in 2H2O. In the frames of proposed research the developing of methods of biological adaptation to obtain [U -2H]labeled biological material with high levels of enrichment are also of a big interest. For this purpose the special biotechnological approaches based on using the strains with improved properties when growing on 2H2O for obtaining fully deuterated DNA and individual proteins should be applied for allowing to prepare [U -2H]labeled macromolecules in gram scale quantities.