Global approaches for protein thiol redox state detection

Due to its nucleophilicity, the thiol group of cysteine is chemifunctions in a protein, be it as the active site or, in extracellular proteins, as part of a structural disulfide. Within the cytosol, cysteines are typically reduced. But the nucleophilicity of its thiol group makes it also particularly prone to post-translational oxidative modifications. These modifications often lead to an alteration of the function of the affected protein and are reversible in vivo, e.g. by the thioredoxin and glutaredoxin system. The in vivo-reversible nature of these modifications and their genesis in the presence of localized high oxidant levels led to the paradigm of thiol-based redox regulation, the adaptation, and modulation of the cellular metabolism in response to oxidative stimuli by thiol oxidation in regulative proteins. Consequently, the proteomic study of these oxidative posttranslational modifications of cysteine plays an indispensable role in redox biology.

Automated summary

Due to its nucleophilicity, the thiol group of cysteine plays an important role in protein chemistry. The nucleophilicity of the thiol group makes cysteine susceptible to oxidative modifications, which can alter protein function and are reversible in vivo. Therefore, studying oxidative posttranslational modifications of cysteine is crucial for understanding redox biology.