The Action of Mercuric Sulfate and Chloride on Cysteine, Cystine, Cysteine Sulfinic Acid (r-so~h), and Cysteic Acid with Reference to the Dismutation of Cystine*

Preceding studies (1) show that one of the products of the dismutation of cystine disulfoxide (R-(SO)z-R) is the sulfinic acid (R-SOZH), a compound which possesses greater stability in solution than any other intermediate oxidation product of cystine obtained thus far. It was interesting, therefore, to determine whether the sulfinic acid results from the dismutation of cystine in the presence of heavy metal salts, especially since published data can be so interpreted. It becomes increasingly evident that many reactions of cystine can be best explained by first assuming that hydrolysis occurs