In biochemistry, beta-alanine is the only naturally occurring beta amino acid, which are amino acids in which the amino group is at the â-position from the carboxylate group (i.e., two atoms away, see Figure 1). The IUPAC name for â-alanine would be 3-aminopropionic acid. Unlike its normal counterpart, L-á-alanine, â-alanine has no chiral center.
â-alanine is not used in the biosynthesis of any major proteins or enzymes. It is formed in vivo by the degradation of dihydrouracil and carnosine. It is a component of the naturally occurring peptides carnosine and anserine and also of pantothenic acid (Vitamin B-5) which itself is a component of coenzyme A. Under normal conditions, beta-alanine is metabolized into acetic acid.
â-alanine is the rate-limiting precursor of carnosine, which is to say carnosine levels are limited by the amount of available â-alanine. Supplementation with â-alanine has been shown to increase the concentration of carnosine in muscles, decrease fatigue in athletes and increase total muscular work done.
Even though much weaker than glycine(and thus with a debated role as a physiological transmitter), beta alanine is an agonist next in activity to the cognate ligant glycine itself, for strychnine-sensitive inhibitory glycine receptors (GlyRs) (the agonist order: glycine>>b-alanine>taurine>>lalanine, l-serine>proline).