Beta-Methylamino-L-alanine

Beta-Methylamino-L-alanine (BMAA) is a non-proteinogenic amino acid produced by cyanobacteria. It was first discovered in the seeds of the cycad genus Cycas, and has since been identified in various other species of cycads. BMAA is a neurotoxin and its potential role in various neurodegenerative diseases is the subject of ongoing research.

Structure and Properties

BMAA is a derivative of alanine with a methylamino group on the beta carbon. It is a polar, zwitterionic compound, and is soluble in water. Its chemical formula is C4H10N2O2.

Biosynthesis

BMAA is produced by cyanobacteria, a group of photosynthetic bacteria that live in a wide variety of habitats. It is synthesized from acetyl-CoA and glycine in a two-step process. First, acetyl-CoA and glycine are condensed by the enzyme glycine N-acyltransferase to form N-acetylglycine. This is then methylated by the enzyme S-adenosyl methionine to produce BMAA.

Toxicity and Disease Association

BMAA is a neurotoxin and has been implicated in several neurodegenerative diseases, including Amyotrophic lateral sclerosis (ALS), Alzheimer's disease, and Parkinson's disease. It is thought to cause damage by being mistakenly incorporated into proteins in place of the amino acid L-serine, leading to protein misfolding and aggregation.

Detection and Quantification

Methods for the detection and quantification of BMAA in biological samples include liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). These techniques allow for the accurate measurement of BMAA concentrations in a variety of sample types, including plant tissues, animal tissues, and environmental samples.

See Also

• Cyanotoxin
• Neurotoxin
• Neurodegenerative disease