STUDIES OF ETHYLENE-FORMING SYSTEM IN RAT-LIVER EXTRACT

Evidence of enzymatic formation of ethylene from methionine by rat liver extracts is presented. The ethylene production is closely associated with growth of the animal. The conversion of l-methionine to ethylene is oxygen dependent. Substrate analogue studies show that the ethylene-forming system is structurally specific and requires in the center of the molecule α-CH2-CH2- with one end attached to an unencumbered sulfur atom from a thioether moiety and the other end attached to a carboxyl group. Sylfhydryl agents are found to be very effective inhibitors of the ethylene-forming system. The finding of α-keto-4-methylthiobutyric acid to be a more efficient precursor of ethylene production suggests the possibility that α-keto-4-methylthiobutyric acid may be an intermediate in the biosynthesis of ethylene from methionine in mammalian tissues. © 1979.