The regulation of transaminative flux of methionine in rat liver mitochondria.

We have demonstrated methanethiol production from methionine in isolated rat liver mitochondria and shown how it is affected by other metabolites. The enzymes involved include several transaminases, branched chain 2-oxoacid dehydrogenase, acyl-CoA dehydrogenase, and crotonase. Methanethiol production from methionine in mitochondria isolated from rat liver was increased by 50% after the rats had been given a single injection of glucagon, but was reduced by 25% when the rats had been starved for 24 h. These results indicate the physiological importance of the transaminative pathway of methionine metabolism.