isoleucine isoleucine isoleucine (symbol ile or i) 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 our diet. in plants isoleucine can be synthesized from threonine and methionine. in plants and bacteria, isoleucine is synthesized from pyruvate employing leucine biosynthesis enzymes. it is encoded by the codons auu, auc, and aua. l-isoleucine skeletal formula of l-isoleucine ball-and-stick model of l-isoleucineball-and-stick model space-filling model of l-isoleucinespace-filling model names iupac name isoleucine other names (2s,3s)-2-amino-3-methylpentanoic acid identifiers cas number 73-32-5 y 3d model (jsmol) interactive imagezwitterion: interactive image chebi chebi:58045 y chemspider 6067 y drugbank db00167 y echa infocard 100.000.726 iuphar/bps 3311 kegg d00065 y pubchem cid 791 unii 04y7590d77 y comptox dashboard (epa) dtxsid1047441 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 ykey: agpkzvbtjjnpag-whfbiakzsa-n yinchi=1/c6h13no2/c1-3-4(2)5(7)6(8)9/h4-5h,3,7h2,1-2h3,(h,8,9)/t4-,5-/m0/s1key: agpkzvbtjjnpag-whfbiakzbb smiles cc(c)(c(=o)o)nzwitterion: cc(c)(c(=o)) 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 , 100 kpa). y verify (what is yn ?) infobox references metabolism biosynthesis in plants and microorganisms, isoleucine is synthesized via several steps starting from pyruvate and alpha-ketobutyrate. as an essential nutrient, this pathway is not present in humans. enzymes involved in this biosynthesis include: acetolactate synthase (also known as acetohydroxy acid synthase) acetohydroxy acid isomeroreductase dihydroxyacid dehydratase valine aminotransferase catabolism isoleucine is both a glucogenic and a ketogenic amino acid. after transamination with alpha-ketoglutarate the carbon skeleton is oxidised and split into propionyl-coa and acetyl-coa. propionyl-coa is converted into succinyl-coa, a tca cycle intermediate which can be converted into oxaloacetate for gluconeogenesis (hence glucogenic). in mammals acetyl-coa cannot be converted to carbohydrate but can be either fed into the tca cycle by condensing with oxaloacetate to form citrate or used in the synthesis of ketone bodies (hence ketogenic) or fatty acids. insulin resistance isoleucine, like other branched-chain amino acids, is associated with insulin resistance: higher levels of isoleucine are observed in the blood of diabetic mice, rats, and humans. mice fed an isoleucine deprivation diet for one day have improved insulin sensitivity, and feeding of an isoleucine deprivation diet for one week significantly decreases blood glucose levels. in diet-induced obese and insulin resistant mice, a diet with decreased levels of isoleucine (with or without the other branched-chain amino acids) results in reduced adiposity and improved insulin sensitivity. reduced dietary levels of isoleucine are required for the beneficial metabolic effects of a low protein diet. in humans, a protein restricted diet lowers blood levels of isoleucine and decreases fasting blood glucose levels. in humans, higher dietary levels of isoleucine are associated with greater body mass index. functions and requirement the food and nutrition board (fnb) of the u.s. institute of medicine has set recommended dietary allowances (rdas) for essential amino acids in 2002. for adults 19 years and older, 19 mg of isoleucine/kg body weight is required daily. beside its biological role as a nutrient, isoleucine also has been shown to participate in regulation of glucose metabolism. isoleucine is an essential component of many proteins. as an essential amino acid, isoleucine must be ingested or protein production in the cell will be disrupted. fetal hemoglobin is one of the many proteins that require isoleucine. isoleucine is present in the gamma chain of fetal hemoglobin and must be present for the protein to form. there are genetic diseases that change the consumption requirements of isoleucine. amino acids cannot be stored in the body. buildup of excess amino acids will cause a buildup of toxic molecules so, humans have many pathways to degrade each amino acid when the need for protein synthesis has been met. mutations in isoleucine-degrading enzymes can lead to dangerous buildup of isoleucine and it's toxic derivative. one example is maple syrup urine disease (msud), a disorder that leaves people unable to breakdown isoleucine, valine, and leucine. people with msud manage their disease by a reduced intake of all three of those amino acids alongside drugs that help excrete built-up toxins. nutritional sources there are many animal and plant-based dietary sources of isoleucine. isoleucine is commonly ingested as a component of proteins. when proteins enter the small intestine they are broken into single amino acids by enzymes known as proteases. free amino acids are taken up by the lining of the digestive tract, mainly in the small intestine, then used in the body. as an essential component of many proteins, animal and plant based protein sources contain isoleucine. foods that have high amounts of isoleucine include eggs, soy protein, seaweed, turkey, chicken, lamb, cheese, and fish. synthesis there are many possible routes to synthesize isoleucine. one common multistep procedure starts from 2-bromobutane and diethylmalonate. synthetic isoleucine was first reported in 1905 by french chemists bouveault and locquin. discovery german chemist felix ehrlich discovered isoleucine while studying the composition of beet-sugar molasses 1903. in 1907 ehrlich carried out further studies on fibrin, egg albumin, gluten, and beef muscle in 1907. these studies verified the natural composition of isoleucine. ehrlich published his own synthesis of isoleucine in 1908. isomers isomer l-allo-isoleucine is the starting material for the production of coronamic acid, which is a constituent of the phytotoxin coronatine, produced by pseudomonas syringae. forms of isoleucine common name:isoleucined-isoleucinel-isoleucinedl-isoleucined-alloisoleucinel-alloisoleucinedl-alloisoleucine synonyms:(r)-isoleucinel(+)-isoleucine(r*,r*)-isoleucinealloisoleucine pubchem:cid 791 from pubchemcid 94206 from pubchemcid 6306 from pubchemcid 76551 from pubchem 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 l-isoleucine (2s,3s) and d-isoleucine (2r,3r) l-alloisoleucine (2s,3r) and d-alloisoleucine (2r,3s)