Cysteine (symbol Cys or C ) is a semiessential proteinogenic amino acid with the formula HS\sCH2\sCH(NH2)\sCOOH. The thiol side chain in cysteine enables the formation of disulfide bonds, and often participates in enzymatic reactions as a nucleophile.
The compounds of every Wikipedia article carrying a Chembox or a Drugbox, refreshed daily, with the values their infoboxes give. The pages need JavaScript; the API does not.