Isoleucine

l-Isoleucine
	; Skeletal formula of L-isoleucine
Ball-and-stick model of L-isoleucine Ball-and-stick model	Space-filling model of L-isoleucine Space-filling model
Names
	IUPAC name Isoleucine
	Other names (2S,3S)-2-amino-3-methylpentanoic acid
Identifiers
CAS Number	73-32-5 ; 443-79-8 D enantiomer; 319-78-8 racemic;
3D model (JSmol)	Interactive image; Zwitterion: Interactive image;
ChEBI	CHEBI:58045 ;
ChemSpider	6067 ;
DrugBank	DB00167 ;
ECHA InfoCard	100.000.726
IUPHAR/BPS	3311;
KEGG	D00065 ;
PubChem CID	791;
UNII	04Y7590D77 ;
CompTox Dashboard (EPA)	DTXSID501096647 DTXSID1047441, DTXSID501096647 ;
	InChI InChI=1S/C6H13NO2/c1-3-4(2)5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t4-,5-/m0/s1 Key: AGPKZVBTJJNPAG-WHFBIAKZSA-N ; InChI=1/C6H13NO2/c1-3-4(2)5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t4-,5-/m0/s1 Key: AGPKZVBTJJNPAG-WHFBIAKZBB;
	SMILES CC[C@H](C)[C@@H](C(=O)O)N; Zwitterion: CC[C@H](C)[C@@H](C(=O)[O-])[NH3+];
Properties
Chemical formula	C6H13NO2
Molar mass	131.175 g·mol−1
Magnetic susceptibility (χ)	−84.9·10−6 cm3/mol
Supplementary data page
	Isoleucine (data page)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Isoleucine (symbol Ile or I)^[1] is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH⁺₃ form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO⁻ form under biological conditions), and a hydrocarbon side chain with a branch (a central carbon atom bound to three other carbon atoms). It is classified as a non-polar, uncharged (at physiological pH), branched-chain, aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it. Essential amino acids are necessary in the human diet. In plants isoleucine can be synthesized from threonine and methionine.^[2] In plants and bacteria, isoleucine is synthesized from pyruvate employing leucine biosynthesis enzymes.^[3] It is encoded by the codons AUU, AUC, and AUA.

^ "IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN). Nomenclature and symbolism for amino acids and peptides. Recommendations 1983". The Biochemical Journal. 219 (2): 345–373. April 1984. doi:10.1042/bj2190345. PMC 1153490. PMID 6743224.
^ Joshi V, Joung JG, Fei Z, Jander G (October 2010). "Interdependence of threonine, methionine and isoleucine metabolism in plants: accumulation and transcriptional regulation under abiotic stress". Amino Acids. 39 (4): 933–947. doi:10.1007/s00726-010-0505-7. PMID 20186554. S2CID 22641155.
^ Kisumi M, Komatsubara S, Chibata I (July 1977). "Pathway for isoleucine formation form pyruvate by leucine biosynthetic enzymes in leucine-accumulating isoleucine revertants of Serratia marcescens". Journal of Biochemistry. 82 (1): 95–103. doi:10.1093/oxfordjournals.jbchem.a131698. PMID 142769.

[1] "IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN). Nomenclature and symbolism for amino acids and peptides. Recommendations 1983". The Biochemical Journal. 219 (2): 345–373. April 1984. doi:10.1042/bj2190345. PMC 1153490. PMID 6743224.

[2] Joshi V, Joung JG, Fei Z, Jander G (October 2010). "Interdependence of threonine, methionine and isoleucine metabolism in plants: accumulation and transcriptional regulation under abiotic stress". Amino Acids. 39 (4): 933–947. doi:10.1007/s00726-010-0505-7. PMID 20186554. S2CID 22641155.

[3] Kisumi M, Komatsubara S, Chibata I (July 1977). "Pathway for isoleucine formation form pyruvate by leucine biosynthetic enzymes in leucine-accumulating isoleucine revertants of Serratia marcescens". Journal of Biochemistry. 82 (1): 95–103. doi:10.1093/oxfordjournals.jbchem.a131698. PMID 142769.

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