The Cobalt-60 Gamma-Radiolysis of Reduced Glutathione in Deaerated Aqueous Solutions

The major products of radiolysis of air-free aqueous solutions of the tripeptide glutathione <tex-math>$ \matrix\format\l\\ ({\rm H}_{3}{}^{+}{\rm NCH}\cdot {\rm CH}_{2}\cdot {\rm CH}_{2}\cdot {\rm CO}\cdot {\rm NH}\cdot {\rm CH}\cdot {\rm CO}\cdot {\rm NH}\cdot {\rm CH}_{2}\cdot {\rm CO}_{2}{}^{-}) \\ \quad \quad \quad \quad \,|\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \,| \\ \quad \quad \quad \quad {\rm CO}_{2}{}^{-}\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \,{\rm CH}_{2}{\rm SH} \endmatrix $</tex-math> are hydrogen, hydrogen sulfide, oxidized glutathione, and γ-glutamylalanylglycine. The last of these results from the replacement of SH by H. There is no evidence for scission of the peptide chain, and the pH dependence and magnitudes of the product yields closely resemble those of the analogous products from cysteine solutions. The radiolytic mechanism is shown to be similar to that for cysteine.