Isoleucine

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, (2//S//,3//S//)-2-amino-3-methylpentanoic acid.
 * Isoleucine** (abbreviated as **Ile** or **I**)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 ingested. Its [|codons] are AUU, AUC and AUA.



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]

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 ||


 * [[image:http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/L-Isoleucin_-_L-Isoleucine.svg/200px-L-Isoleucin_-_L-Isoleucine.svg.png width="200" height="104" caption="L-Isoleucin - L-Isoleucine.svg" link="http://en.wikipedia.org/wiki/File:L-Isoleucin_-_L-Isoleucine.svg"]] [[image:http://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/D-isoleucine.svg/200px-D-isoleucine.svg.png width="200" height="114" caption="D-isoleucine.svg" link="http://en.wikipedia.org/wiki/File:D-isoleucine.svg"]] ||
 * L -isoleucine (2//S//,3//S//) and D -isoleucine (2//R//,3//R//) ||
 * [[image:http://upload.wikimedia.org/wikipedia/commons/thumb/4/41/L-alloisoleucine.svg/200px-L-alloisoleucine.svg.png width="200" height="114" caption="L-alloisoleucine.svg" link="http://en.wikipedia.org/wiki/File:L-alloisoleucine.svg"]] [[image:http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/D-alloisoleucine.svg/200px-D-alloisoleucine.svg.png width="200" height="114" caption="D-alloisoleucine.svg" link="http://en.wikipedia.org/wiki/File:D-alloisoleucine.svg"]] ||
 * L -//allo//-isoleucine (2//S//,3//R//) and D -//allo//-isoleucine (2//R//,3//S//) ||

Synthesis
Isoleucine can be synthesized in a multistep procedure starting from [|2-bromobutane] and [|diethylmalonate]. [|[5]] Synthetic isoleucine was originally reported in 1905. [|[6]] German chemist [|Felix Ehrlich] discovered isoleucine in [|hemoglobin] in 1903.

Isoleucine is an essential amino acid and is part of the three "branched chain amino acids" (BCAA) - the other two being leucine and valine. This amino acid cannot be manufactured in the body, and needs to be supplied in the diet and was first isolated in 1904 from fibrin. Isoleucine, together with the other two branched-chain-amino-acids promote muscle recovery after physical exercise and on its own it is needed for the formation of hemoglobin as well as assisting with regulation of blood sugar levels as well as energy levels. It is also involved in blood-clot formation.

 Deficiency of isoleucine is only found in people deficient in dietary protein but symptoms may include headaches, dizziness, fatigue, depression, confusion as well as irritability. Symptoms of deficiency may mimic the symptoms of hypoglycemia. This nutrient has also been found to be deficient in people with mental and physical disorders, but more research is required on this.