# Reaction of aqueous mercury(II) chloride with cysteine?

I know that thiols react with mercury (which is why they were originally known as mercaptans). I haven’t been able to determine what this reaction actually is. If I add HgCl$$_2$$ to a solution containing cysteine (or proteins with cysteines in the reduced thiol form), what happens? What product is formed? Does the reaction only happen with the thiolate form (so the reaction is pH dependent)?

• Well, you get a complex with two cysteines, coordinating with S and N - at least as far as I can tell. – Mithoron Sep 25 at 23:42