Isoleucine

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(2S,3S)-2-amino-3-methylpentanoic acid
Chemical structure of Isoleucine
Chemical structure of Isoleucine
Identifiers
CAS number
PubChem 791
SMILES CC[C@H](C)[C@H](N)C(O)=O
Properties
Molecular formula C6H13NO2
Molar mass 131.17 g mol-1
Supplementary data page
Structure and
properties		 n, εr, etc.
Thermodynamic
data		 Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Isoleucine (abbreviated as Ile or I)[1] is an α-amino acid with the chemical formula HO2CCH(NH2)CH(CH3)CH2CH3. It is an essential amino acid, which means that humans cannot synthesize it, so it must be part of our diet. Its codons are AUU, AUC and AUA.

With a hydrocarbon side chain, isoleucine is classified as a hydrophobic amino acid. Together with threonine, isoleucine is one of two common amino acids that have a chiral side chain. Four stereoisomers of isoleucine are possible, including two possible diastereomers of L-isoleucine. However, isoleucine present in nature exists in one enantiomeric form, (2S,3S)-2-amino-3-methylpentanoic acid.

Contents

[edit] Biosynthesis

As an essential amino acid, isoleucine is not synthesized in animals, hence it must be ingested, usually as a component of proteins. In plants and microorganisms, it is synthesized via several steps, starting from pyruvic acid and alpha-ketoglutarate. Enzymes involved in this biosynthesis include:[2]

  1. Acetolactate synthase (also known as acetohydroxy acid synthase)
  2. Acetohydroxy acid isomeroreductase
  3. Dihydroxyacid dehydratase
  4. Valine aminotransferase

[edit] Isomers of isoleucine

Forms of Isoleucine
Common name: isoleucine D-isoleucine L-isoleucine DL-isoleucine allo-D-isoleucine allo-L-isoleucine allo-DL-isoleucine
Synonyms: (R)-Isoleucine L(+)-Isoleucine (R*,R*)-isoleucine alloisoleucine
PubChem: CID 791 CID 94206 CID 6306 CID 76551
EINECS number: 207-139-8 206-269-2 200-798-2 216-143-9 216-142-3 221-464-2
CAS number: 443-79-8 319-78-8 73-32-5 1509-35-9 1509-34-8 3107-04-8

[edit] Synthesis

Isoleucine can be synthesized in a multistep procedure starting from 2-bromobutane and diethylmalonate.[3] Synthetic isoleucine was originally reported in 1905.[4]

[edit] References

  1. ^ IUPAC-IUBMB Joint Commission on Biochemical Nomenclature. Nomenclature and Symbolism for Amino Acids and Peptides. Recommendations on Organic & Biochemical Nomenclature, Symbols & Terminology etc. Retrieved on 2007-05-17.
  2. ^ Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. ISBN 1-57259-153-6.
  3. ^ (1955) "dl-Isoleucine". Org. Synth.; Coll. Vol. 3: 495. 
  4. ^ Bouveault and Locquin, Compt. rend., 141, 115 (1905).

[edit] External links

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