A guanine ethylthioethyl glutathione adduct as a major DNA lesion in the skin and in organs of mice exposed to sulfur mustard ScienceDirect Frontiers Redox regulation of enzymes involved in sulfate assimilation and in the synthesis of sulfur containing amino acids and glutathione in plants Potential Role of Sulfur Containing Antioxidant Systems in Highly Oxidative Environments Sulfur metabolism under stress: Oxidized glutathione inhibits methionine biosynthesis by destabilizing the enzyme cystathionine < em> synthase