The system VO2+ +oxidized glutathione:: a potentiometric and spectroscopic study

The equilibria in the system VO2++oxidized glutathione in aqueous solution have been studied in the pH range 2-11 by a combination of pH potentiometry and spectroscopy (EPR, visible absorption and circular dichroism). The results of the various methods are self-consistent and the equilibrium model includes the species MLH4, MLH3, MLH2, MLH. ML, MLH-1, MLH-2 and several hydrolysis products (where H4L denotes oxidized glutathione); individual formation constants and spectra are given. Plausible structures for each stoichiometry are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.