[The effect of oxygen on denaturation and aggregation of enzyme macromolecules during gamma-irradiation]

The ribonuclease molecules irradiated in a solution in the presence of 18O2 were separated, by the method of gel-chromatography, into fractions of aggregated macromolecules, denatured monomers and the molecules which retained the original sizes. Oxygen was bound by the molecules of all fractions. The oxygen binding prevented the aggregation of macromolecules. The fractions of molecules of monomer forms, obtained after irradiation in the presence of oxygen, were more inactive than those obtained after irradiation in vacuum.