[Structural flexibility of canonical 2'-deoxyribonucleotides in DNA-like conformations].

Quantitative characteristics of structural flexibility of the DNA elementary monomer units -5'-deoxycytidylic, 5'-thymidylic, 5'-deoxyadenylic and 5'-deoxyguanylic acid molecules--have been calculated with original methods. Root-mean-square deviations from equilibrium for all conformational parameters, caused by nuclei thermal or quantum zero-point vibrations, have been found to lie within 4 degrees divided by 25 degrees at 0 K and 7 degrees divided by 50 degrees at 298 K and corresponding relaxed force constants--within 1 divided by 35 kcal/mol x rad(-2). Their values have been found to be sensitive to the molecule's conformation. It has been proven, that the torsion angle gamma is the most rigid one whereas relaxed force constants for all other conformational variables are lower and comparable to each other. The data obtained could serve for development of structural-dynamical models of the DNA.