Methionine is a nutritionally indispensable amino acid, and is unique among indispensable
amino acids due to its sulfur atom. Methionine is involved in cysteine synthesis via the
transsulfuration pathway, which is rate limiting for the key antioxidant molecule, glutathione.
Methionine is also the primary methyl donor in the body through Sadenosylmethionine via
the transmethylation pathway, which is involved in the synthesis of several key metabolites
including creatine and phosphatidylcholine. Methionine can also be remethylated from …