STRUCTURE OF THE INTRASTRAND CIS-[PT(NH3)2(D(GPCPG))] ADDUCT IN A DODECANUCLEOTIDE DUPLEX .1. A H-1 AND P-31 NMR-STUDY

  • 1 June 1989
    • journal article
    • research article
    • Vol. 4  (1) , 53-61
Abstract
The structure of an intrastand cis-[Pt(NH3)2{d(GpCpG)}] adduct in a dodecanucleotide duplex has been investigated by using ultraviolet absorption, circular dichroism, 1H and 31P n.m.r. The binding of cis-DDP does not inhibit the formation of a duplex but it induces a lowering of .simeq. 26.degree. C of its melting temperature. A broadening of the 1H spectrum prevents an accurate analysis of the platination site. Nevertheless, by considering its thermal behavior and the number of imino protons a model of structure of the platinated duplex is proposed in which the central C.G. pair is disrupted and a neighboring C.G. pair is very accessible or distorted. The environment of two phosphate groups is disturbed by the cis-DDP binding.