S-Adenosyl methionine

• SAM
• AdoMet
• S-adenosyl- L-methionine

A16AA02

Template: Infobox chemical / molecular formula search available

S- adenosylmethionine, named SAM or AdoMet is a key product in the metabolism of the amino acid methionine. It results from this by reaction with adenosine triphosphate ( ATP). SAM occurs in metabolism as a methyl donor, and it is hydrolyzed even S- adenosyl homocysteine ​​to adenosine and homocysteine. Homocysteine ​​can again remethylated to methionine or cysteine ​​amino acid to be reduced.

History

Giulio Cantoni discovered in 1952 the S -adenosylmethionine and explored its significance and chemistry. Only in recent years discovered its importance as a drug. In the United States and the European Union S- adenosylmethionine is sold as a dietary supplement. This was made possible by the Dietary Supplement Health and Education Act of 1999., This law allows for dietary supplements to circumvent the Food and Drug Administration (FDA).

Biosynthesis

SAM is synthesized in cells from methionine and ATP by the enzyme methionine -adenosyl transferase in the presence of divalent cations such as Mg2 , Co2 or Mn2 . For genetically modified Escherichia coli strains, the presence of certain monovalent metal cations caused a marked stimulation of SAM production.

Properties and biological significance

The highly reactive methyl group on the sulfonium group of SAM is involved in the metabolism of so-called trans- methylation, which is transferred or introduced a methyl group. These reactions are catalysed by enzymes called methyltransferases using SAM as a substrate. Such trans- methylation reactions are important steps in the biosynthesis of several neurotransmitters, such as adrenaline or acetylcholine. Even the better-known as lecithin, phosphatidylcholines need for her portrayal SAM. The neurotransmitter histamine is inactivated, including through the SAM-dependent histamine -N- methyltransferase. Further SAM plays in DNA methylation by DNA methyltransferases in eukaryotes a major role.

Medical Application

The broad activity of the SAM as a drug includes treatment of depression, arthritis, and liver disease.

Side effects

The following side effects may occur with SAM in the treatment: Stomach upset, diarrhea, anxiety, manic symptoms, headache, insomnia and allergic reactions. The impact occurring after long-term treatment are unknown.

Inducing manic symptoms

In people with bipolar disorder is by taking SAM the risk of the formation of manic symptoms, as this is also possible with other antidepressants. Clinical studies have also shown that oral or injected doses of the compound can cause manic symptoms in patients without previously diagnosed Bipolar Disorder. Some symptoms such as cognitive dysfunction may persist even after discontinuation of the medication.