"The simplest organic molecule contains a single carbon surrounded by 4 atoms of hydrogen. Called methane, it has the shape of a perfect 4-sided pyramid called a tetrahedron. In this structure, the carbon is in the very center of the pyramid shape and a hydrogen atom occupies each of the 4 corners.

If a hydrogen atom is removed from one corner of the methane pyramid, the carbon atom in the center can now bond with another atom. The chemical group just formed - with a carbon and three hydrogen atoms - is called a methyl group." (Description from The Chemistry of Life Extension.) The process of adding a methyl group to a molecule, is methylation. It takes place in every cell in the body.

• From Great Smokies Diagnostic Lab's April 2000 newsletter: "first an "adenosyl" group from ATP is attached to methionine to form S-adenosyl-methionine (SAM) by an enzymatic process that needs magnesium. With the help of a methyltransferase enzyme, SAM can then give away the methyl group that is carried on the methionine portion. When it does this, SAM becomes S-adenosylhomocysteine (SAH)." [In the US, SAM is sold as a nutritional supplement under the marketing name SAMe.]
• involved with
  • protein production
  • DNA regulation
  • neurotransmitter production
• required for the production of melatonin.
• detoxifies
  • cobalamin
  • histamine
  • adrenal catecholamines (epinephrine, norepinephrine)
  • serotonin
  • phosphatidylethanolamine (successive methylation produces choline)
  • tryptamine
  • tyramine
  • amphetamine
  • aniline, benzidine, imidazole
  • arsenic, antimony, selenium. "For arsenic, SAM reacts twice with arsonic acid to produce dimethylarsinic acid (also called cacodylic acid). Similar methylation detoxifies antimony and selenium, and hydrogen sulfide." [GSDL again]
  • hydrogen sulfide — becomes (CH3)2S.
• protects against cancer, especially in the liver

Endogenous production

• requires
  • methyl donors
  • methionine synthetase

Defects

• critical enzyme methionine synthetase is inhibited by heavy metals and other toxins

Supplementation

• methyl donors

Testing

• Since homocysteine rises when methylation is deficient, might a blood test for homocysteine level be a simple way to determine methylation status? See "A Lethal Misconception."

For more information

• Enzymes & Methylation
• Methionine Cycle and Glutathione - includes references