Protein mixed-disulfides in cardiac cells. S-thiolation of soluble proteins in response to diamide.

Protein mixed-disulfides in cultured rat heart cells were analyzed by gel electrophoresis under conditions that eliminated artifactual formation of these protein derivatives. Protein S-thiolation (protein mixed-disulfide formation) was detectable under normal culture conditions. Diamide oxidized intracellular glutathione in these cells and produced extensive protein S-thiolation. The specificity of this protein modification indicates a role in the regulation of cardiac metabolism.