Oxidative Cleavage of Peptide and Protein Disulphide Bonds by Gold(II1): a Mechanism for Gold Toxicity ... By PATRICIA L. WITKIEWICZ and C. FRANK SHAW III* (Department of Chemistry and The Laboratory for Molecular Biomedical Research, The University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201) ... Summary The oxidative cleavage of disulphide bonds to form the sulphonic acid derivatives is shown to be an important ...