Some Effects of Ionizing Radiation on Methionine Sulfonium Compounds

Abstract
S-Adenosylmethionine and S-methylmethionine show no unusual sensitivity toward X- and gamma-irradiation, resembling methionine and adenosine in this respect. S-Adenosylmethionine, located after biosynthesis in the vacuoles of yeast cells, is not released by 400 kr of X-irradiation. The enzymatic synthesis of the sulfonium compound, including formation of the purine and ribose structure from simple precursors, was virtually unimpeded after exposure of the yeast cells to 400 kr of X-irradiation or to 1.0 Mrad of gamma-irradiation.