Dynamic behaviour of oxidized glutathione in solution investigated by nuclear magnetic resonance

In view of the important biological functions of oxidized glutathione (GSSG), we investigated the correlation between dynamic and conformational properties and biological activity. Anisotropic molecular motion characterizes different GSSG molecular districts. This information, obtained by NMR carbon relaxation investigations, suggests that the peptide does not independently assume any stable structure in solution. Analysis of the effects of the addition of a stable spin label to the solution confirmed the absence of conformation of GSSG in D 2 O. Moreover, the paramagnetic effects observed on proton and carbon nuclei of oxidized glutathione suggest that the dipolar term is the main source of paramagnetic relaxation.