Mercury, cadmium and other heavy metals have a high affinity for sulfhydryl groups, inactivating enzymatic reactions, amino acids, and sulfur - containing antioxidants. (nutritionalbalancing.org)
Maleimide - labeling occurs when a maleimide group forms a covalent bond with a sulfhydryl group -LRB--- SH), such as that found in cysteine. (blog.addgene.org)
The sulfhydryl (often referred to as thiol) group on the cysteine acts almost like a lint roller for the toxic free radicals produced during oxidative stress. (theivdoc.com)