2-Aminoisobutyric acid
2-methylalanine molecule
Names
Preferred IUPAC name
2-Amino-2-methylpropanoic acid
Other names
α-Aminoisobutyric acid
2-Methylalanine
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
DrugBank
ECHA InfoCard 100.000.495 Edit this at Wikidata
EC Number
  • 200-544-0
KEGG
UNII
  • InChI=1S/C4H9NO2/c1-4(2,5)3(6)7/h5H2,1-2H3,(H,6,7) checkY
    Key: FUOOLUPWFVMBKG-UHFFFAOYSA-N checkY
  • InChI=1/C4H9NO2/c1-4(2,5)3(6)7/h5H2,1-2H3,(H,6,7)
    Key: FUOOLUPWFVMBKG-UHFFFAOYAD
  • O=C(O)C(N)(C)C
Properties
C4H9NO2
Molar mass 103.12 g/mol
Appearance white crystalline powder
Density 1.09 g/mL
Boiling point 204.4 °C (399.9 °F; 477.5 K)
soluble
Acidity (pKa)
  • 2.36 (carboxyl; H2O)
  • 10.21 (amino; H2O)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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2-Aminoisobutyric acid (also known as α-aminoisobutyric acid, AIB, α-methylalanine, or 2-methylalanine) is the non-proteinogenic amino acid with the structural formula H2N-C(CH3)2-COOH. It is rare in nature, having been only found in meteorites,[2] 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.[3] Industrial scale synthesis can be achieved by the selective hydroamination of methacrylic acid.

Biological activity

2-Aminoisobutyric acid is not one of the proteinogenic amino acids and is rather rare in nature (cf. non-proteinogenic amino acids). It is a strong helix inducer in peptides due to Thorpe–Ingold effect of its gem-dimethyl group.[4] Oligomers of AIB form 310 helices.

Ribosomal incorporation into peptides

See also: Cell-free system and Cell-free protein synthesis

2-Aminoisobutyric acid is compatible with ribosomal elongation of peptide synthesis. Katoh et al. used flexizymes[5] and an engineered a tRNA body to enhance the affinity of aminoacylated AIB-tRNA species to elongation factor P.[6] 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-tRNAVal. The aminoacylated tRNA was subsequently used in a cell-free translation system to yield AIB-containing peptides.[7]

References

  1. ^ Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. p. 5–88. ISBN 978-1498754286.
  2. ^ "Immune System of Humans, Other Mammals Could Struggle to Fight Extraterrestrial Microorganisms". Science News. 23 July 2020. Retrieved 24 July 2020.
  3. ^ Clarke, H. T.; Bean, H. J. (1931). "α-Aminoisobutyric acid". Organic Syntheses. 11: 4; Collected Volumes, vol. 2, p. 29..
  4. ^ Toniolo, C.; Crisma, M.; Formaggio, F.; Peggion, C. (2001). "Control of peptide conformation by the Thorpe-Ingold effect (C alpha-tetrasubstitution)". Biopolymers. 60 (6): 396–419. doi:10.1002/1097-0282(2001)60:6<396::AID-BIP10184>3.0.CO;2-7. ISSN 0006-3525. PMID 12209474.
  5. ^ Ohuchi, Masaki; Murakami, Hiroshi; Suga, Hiroaki (2007). "The flexizyme system: a highly flexible tRNA aminoacylation tool for the translation apparatus". Current Opinion in Chemical Biology. 11 (5): 537–542. doi:10.1016/j.cbpa.2007.08.011. PMID 17884697.
  6. ^ Katoh, Takayuki; Iwane, Yoshihiko; Suga, Hiroaki (2017-12-15). "Logical engineering of D-arm and T-stem of tRNA that enhances d-amino acid incorporation". Nucleic Acids Research. 45 (22): 12601–12610. doi:10.1093/nar/gkx1129. ISSN 0305-1048. PMC 5728406. PMID 29155943.
  7. ^ Iqbal, Emil S.; Dods, Kara K.; Hartman, Matthew C. T. (2018). "Ribosomal incorporation of backbone modified amino acids via an editing-deficient aminoacyl-tRNA synthetase". Organic & Biomolecular Chemistry. 16 (7): 1073–1078. doi:10.1039/c7ob02931d. ISSN 1477-0539. PMC 5993425. PMID 29367962.
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