PubChem = 1182
CAS = 72-18-4
SMILES = CC(C)C(N)C(=O)O
C=5 | H=11 | N=1 | O=2
Valine (abbreviated as Val or V) [cite web | author=IUPAC-IUBMB Joint Commission on Biochemical Nomenclature | title=Nomenclature and Symbolism for Amino Acids and Peptides | work=Recommendations on Organic & Biochemical Nomenclature, Symbols & Terminology etc | url=http://www.chem.qmul.ac.uk/iupac/AminoAcid/ | accessdate=2007-05-17] is an α-
amino acidwith the chemical formulaHO2CCH(NH2)CH(CH3)2. L-Valine is one of 20 proteogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acidis classified as nonpolar. Along with leucineand isoleucine, valine is a branched-chain amino acid. It is named after the plant valerian. In sickle-cell disease, valine substitutes for the hydrophilic amino acid glutamic acidin hemoglobin. Because valine is hydrophobic, the hemoglobin does not fold correctly.
Valine is an essential amino acid, hence it must be ingested, usually as a component of proteins. It is synthesized in plants via several steps starting from
pyruvic acid. The initial part of the pathway also leads to leucine. The intermediate α-ketovalerate undergoes reductive amination with glutamate. Enzymes involved in this biosynthesis include: [Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. ISNB 1-57259-153-6.]
Acetolactate synthase(also known as acetohydroxy acid synthase)
Acetohydroxy acid isomeroreductase
Racemic valine can be synthesized by bromination of isovaleric acid followed by amination of the α-bromo derivative [Marvel, C. S. “d,l-Valine” Organic Syntheses, Collected Volume 3, p.848 (1955). http://www.orgsyn.org/orgsyn/pdfs/CV3P0848.pdf] :HO2CCH2CH(CH3)2 + Br2 → HO2CCHBrCH(CH3)2 + HBr:HO2CCHBrCH(CH3)2 + 2 NH3 → HO2CCH(NH2)CH(CH3)2 + NH4Br
Nutritional sources of valine include cottage cheese, fish, poultry, peanuts, sesame seeds, and lentils.
* [http://www.chem.qmul.ac.uk/iubmb/enzyme/reaction/AminoAcid/IleVal.html Isoleucine and valine biosynthesis]
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