Enzymatic formation of glyceryl and phosphoglyceryl methylthiol esters.

Methyl mercaptan is a naturally occurring compound known to be formed and utilized by living organisms. It can arise in microorganisms (1) and in the rat (2) from methionine. It is rapidly oxidized in the rat, and its methyl carbon atom is incorporated into a number of compounds in this animal (3). In yeast cultures it promotes the accumulation of thiomethyl adenosine (4). Reported here is a recently found enzymatic process involving MeSH.’ Incubation of this substance with PGA in a crude yeast extract results in the formation of glyceryl methylthiol ester. The latter has been isolated from a reaction mixture and crystallized. A study of the reactions involved in GMTE formation resulted in the separation of two enzyme fractions. One fraction catalyzes the formation of phosphoglyceryl methylthiol ester from PGA, MeSH, and ATP, as indicated in Reaction 1.