2-Aminoisobutyric acid

2-Aminoisobutyric acid is the non-proteinogenic amino acid with the structural formula H₂N-C₂-COOH. It is rare in nature, having been only found in meteorites, and some antibiotics of fungal origin, such as alamethicin and some lantibiotics.

Synthesis

In the laboratory, 2-aminoisobutyric acid may be prepared from acetone cyanohydrin, by reaction with ammonia followed by hydrolysis.
Industrial scale synthesis could be achieved by the selective hydroamination of methacrylic acid, although this specific reaction has not been reported.

Biological activity

2-Aminoisobutyric acid is not one of the proteinogenic amino acids and is rather rare in nature. It is a strong helix inducer in peptides due to Thorpe–Ingold effect of its gem-dimethyl group. Oligomers of AIB form 3₁₀ helices.

Ribosomal incorporation into peptides

2-Aminoisobutyric acid is compatible with ribosomal elongation of peptide synthesis. Katoh et al. used flexizymes and an engineered tRNA body to enhance the affinity of aminoacylated AIB-tRNA species to elongation factor P. The result was an increased incorporation of AIB into peptides in a cell free translation system. Iqbal et al.. used an alternative approach of creating an editing deficient valine—tRNA ligase to synthesize aminoacylated AIB-tRNA^Val. The aminoacylated tRNA was subsequently used in a cell-free translation system to yield AIB-containing peptides.