[Infrared spectroscopic study of DNA--lipid interactions. DNA compacting on disperse particles]

Within the range of relative humidity (r. h.) 0 to 92% there were obtained IR-spectra (4000--900 cm-1) of undeuterated and deuterated films of rat liver lipids, both in the free state and in the complex with native (nDNA) and heat-denaturated DNA (dDNA). Found peculiarities of IR-spectroscopic realization of the complex-formation are explained qualitatively. One of the peculiarities is hyperchromism of lipid bands and hypochromism of the bands of DNA bases. Lipids are shown to despiralize nDNA in the course of their interaction. A suggestion is advanced concerning the nature of basic contacts which form the complex DNA-lipid. It is found that nDNA unlike dDNA produces an inhibiting effect on lipids oxidation and their subsequent hydrolysis. The mechanism of the phenomenon is discussed. The ideas on DNA compactization resulting from its coiling on different protein and nonprotein particles are developed.