... machinery, allowing the formation of glutathione (GSH) by the action of the rate-limiting enzyme, γ-glutamylcysteine synthetase (γ-GCS). The activity of γ-GCS is irreversibly blocked by L-buthionine-(S,R)-sulfoximine ... augmented by oxidative stress. Synthesized by the action of the rate-limiting enzyme γ-glutamylcysteine synthetase [47–50,107,108] glutathione uniquely provides a functional cysteinyl moiety that ... supporting the hypothesis that these metal atoms can sub-stitute for the iron atom within the heme moiety, and that the oxygen sensor for the induction of EPO is a heme protein [59–61,64,65]. Further...