THE STUDY OF THE STABILITY OF WATSON-CRICK NUCLEIC-ACID BASE-PAIRS INWATER AND DIMETHYL-SULFOXIDE - COMPUTER-SIMULATION BY THE MONTE-CARLOMETHOD

An extensive computer simulation of nucleic acid bases and Watson-Cric k base pairs in a water cluster and DMSO cluster is performed by the M onte Carlo method. It is demonstrated that the unfavorable energetics of pair formation in a water cluster is determined by the significant destabilizing contribution of solvent to the energy of complex formati on. It is shown that the formation of coplanar base pairs in a DMSO cl uster is favorable. The DMSO cluster stabilizes A-U and A-T base pairs and the insignificant destabilization of the G-C base pair by a DMSO cluster is much less than the stabilization which occurs due to the at traction between bases.