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Valine

January 12, 2023

Valine (symbol Val or V)[4] is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain isopropyl group, making it a non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, beans and legumes. It is encoded by all codons starting with GU (GUU, GUC, GUA, and GUG).

Valine
Skeletal formula of neutral valine
Names
IUPAC name
Valine
Other names
2-Amino-3-methylbutanoic acid
Identifiers
  • L: 72-18-4 Y
  • D/L: 516-06-3 Y
  • D: 640-68-6 Y
3D model (JSmol)
  • L: Interactive image
  • L Zwitterion: Interactive image
ChEBI
  • L: CHEBI:16414 Y
ChEMBL
  • L: ChEMBL43068 Y
ChemSpider
  • L: 6050 Y
  • D/L: 1148 Y
  • D: 64635 Y
DrugBank
  • L: DB00161 Y
ECHA InfoCard 100.000.703
EC Number
  • L: 200-773-6
  • L: 4794
KEGG
  • L: D00039 Y
  • L: 6287
  • D/L: 1182
  • D: 71563
UNII
  • L: HG18B9YRS7 Y
  • D/L: 4CA13A832H Y
  • D: Y14I1443UR Y
  • L: DTXSID40883233
  • InChI=1S/C5H11NO2/c1-3(2)4(6)5(7)8/h3-4H,6H2,1-2H3,(H,7,8)/t4-/m0/s1 Y
    Key: KZSNJWFQEVHDMF-BYPYZUCNSA-N Y
  • D/L: Key: KZSNJWFQEVHDMF-UHFFFAOYSA-N
  • D: Key: KZSNJWFQEVHDMF-SCSAIBSYSA-N
  • L: CC(C)[C@@H](C(=O)O)N
  • L Zwitterion: CC(C)[C@@H](C(=O)[O-])[NH3+]
Properties[3]
C5H11NO2
Molar mass 117.148 g·mol−1
Density 1.316 g/cm3
Melting point 298 °C (568 °F; 571 K) (decomposition)
soluble, 85 g/L [1]
Acidity (pKa) 2.32 (carboxyl), 9.62 (amino)[2]
-74.3·10−6 cm3/mol
Supplementary data page
Valine (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

History and etymology

Valine was first isolated from casein in 1901 by Hermann Emil Fischer.[5] The name valine comes from valeric acid, which in turn is named after the plant valerian due to the presence of the acid in the roots of the plant.[6][7]

Nomenclature

According to IUPAC, carbon atoms forming valine are numbered sequentially starting from 1 denoting the carboxyl carbon, whereas 4 and 4' denote the two terminal methyl carbons.[8]

Metabolism

Source and biosynthesis

Valine, like other branched-chain amino acids, is synthesized by plants, but not by animals.[9] It is therefore an essential amino acid in animals, and needs to be present in the diet. Adult humans require about 24 mg/kg body weight daily.[10] It is synthesized in plants and bacteria via several steps starting from pyruvic acid. The initial part of the pathway also leads to leucine. The intermediate α-ketoisovalerate undergoes reductive amination with glutamate. Enzymes involved in this biosynthesis include:[11]

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

Degradation

Like other branched-chain amino acids, the catabolism of valine starts with the removal of the amino group by transamination, giving alpha-ketoisovalerate, an alpha-keto acid, which is converted to isobutyryl-CoA through oxidative decarboxylation by the branched-chain α-ketoacid dehydrogenase complex.[12] This is further oxidised and rearranged to succinyl-CoA, which can enter the citric acid cycle.

Synthesis

Racemic valine can be synthesized by bromination of isovaleric acid followed by amination of the α-bromo derivative[13]

HO2CCH2CH(CH3)2 + Br2 → HO2CCHBrCH(CH3)2 + HBr
HO2CCHBrCH(CH3)2 + 2 NH3 → HO2CCH(NH2)CH(CH3)2 + NH4Br

Medical significance

Insulin resistance

Lower levels of serum valine, like other branched-chain amino acids, are associated with weight loss and decreased insulin resistance: higher levels of valine are observed in the blood of diabetic mice, rats, and humans.[14] Mice fed a BCAA-deprived diet for one day had improved insulin sensitivity, and feeding of a valine-deprived diet for one week significantly decreases blood glucose levels.[15] In diet-induced obese and insulin resistant mice, a diet with decreased levels of valine and the other branched-chain amino acids resulted in a rapid reversal of the adiposity and an improvement in glucose-level control.[16] The valine catabolite 3-hydroxyisobutyrate promotes insulin resistance in mice by stimulating fatty acid uptake into muscle and lipid accumulation.[17] In mice, a BCAA-restricted diet decreased fasting blood glucose levels and improved body composition.[18]

Hematopoietic stem cells

Dietary valine is essential for hematopoietic stem cell (HSC) self-renewal, as demonstrated by experiments in mice.[19] Dietary valine restriction selectively depletes long-term repopulating HSC in mouse bone marrow. Successful stem cell transplantation was achieved in mice without irradiation after 3 weeks on a valine restricted diet. Long-term survival of the transplanted mice was achieved when valine was returned to the diet gradually over a 2-week period to avoid refeeding syndrome.

See also

References

  1. ^ "Physicochemical Information". emdmillipore. 2022. Retrieved 17 November 2022.{{cite web}}: CS1 maint: url-status (link)
  2. ^ Dawson RM, Elliott DC, Elliott WH, Jones KM, eds. (1959). Data for Biochemical Research. Oxford: Clarendon Press. ASIN B000S6TFHA. OCLC 859821178.
  3. ^ Weast RC, ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-569. ISBN 0-8493-0462-8.
  4. ^ "Nomenclature and Symbolism for Amino Acids and Peptides". IUPAC-IUB Joint Commission on Biochemical Nomenclature. 1983. from the original on 9 October 2008. Retrieved 5 March 2018.
  5. ^ "Valine". Encyclopædia Britannica Online. Retrieved 6 December 2015.
  6. ^ "Valine". Merriam-Webster Online Dictionary. Retrieved 6 December 2015.
  7. ^ "Valeric acid". Merriam-Webster Online Dictionary. Retrieved 6 December 2015.
  8. ^ Jones JH, ed. (1985). Amino Acids, Peptides and Proteins. Specialist Periodical Reports. Vol. 16. London: Royal Society of Chemistry. p. 389. ISBN 978-0-85186-144-9.
  9. ^ Basuchaudhuri P (2016). Nitrogen metabolism in rice. Boca Raton, Florida: CRC Press. p. 159. ISBN 978-1-4987-4668-7. OCLC 945482059.
  10. ^ Institute of Medicine (2002). "Protein and Amino Acids". Dietary Reference Intakes for Energy, Carbohydrates, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. pp. 589–768. doi:10.17226/10490. ISBN 978-0-309-08537-3.
  11. ^ Lehninger, Albert L.; Nelson, David L.; Cox, Michael M. (2000). Principles of Biochemistry (3rd ed.). New York: W. H. Freeman. ISBN 1-57259-153-6..
  12. ^ Mathews CK (2000). Biochemistry. Van Holde, K. E., Ahern, Kevin G. (3rd ed.). San Francisco, Calif.: Benjamin Cummings. p. 776. ISBN 978-0-8053-3066-3. OCLC 42290721.
  13. ^ Marvel CS (1940). "dl-Valine". Organic Syntheses. 20: 106.; Collective Volume, vol. 3, p. 848.
  14. ^ Lynch CJ, Adams SH (December 2014). "Branched-chain amino acids in metabolic signalling and insulin resistance". Nature Reviews. Endocrinology. 10 (12): 723–36. doi:10.1038/nrendo.2014.171. PMC 4424797. PMID 25287287.
  15. ^ Xiao F, Yu J, Guo Y, Deng J, Li K, Du Y, et al. (June 2014). "Effects of individual branched-chain amino acids deprivation on insulin sensitivity and glucose metabolism in mice". Metabolism. 63 (6): 841–50. doi:10.1016/j.metabol.2014.03.006. PMID 24684822.
  16. ^ Cummings NE, Williams EM, Kasza I, Konon EN, Schaid MD, Schmidt BA, et al. (February 2018). "Restoration of metabolic health by decreased consumption of branched-chain amino acids". The Journal of Physiology. 596 (4): 623–645. doi:10.1113/JP275075. PMC 5813603. PMID 29266268.
  17. ^ Jang C, Oh SF, Wada S, Rowe GC, Liu L, Chan MC, et al. (April 2016). "A branched-chain amino acid metabolite drives vascular fatty acid transport and causes insulin resistance". Nature Medicine. 22 (4): 421–6. doi:10.1038/nm.4057. PMC 4949205. PMID 26950361.
  18. ^ Fontana L, Cummings NE, Arriola Apelo SI, Neuman JC, Kasza I, Schmidt BA, et al. (July 2016). "Decreased Consumption of Branched-Chain Amino Acids Improves Metabolic Health". Cell Reports. 16 (2): 520–530. doi:10.1016/j.celrep.2016.05.092. PMC 4947548. PMID 27346343.
  19. ^ Taya Y, Ota Y, Wilkinson AC, Kanazawa A, Watarai H, Kasai M, et al. (December 2016). "Depleting dietary valine permits nonmyeloablative mouse hematopoietic stem cell transplantation". Science. 354 (6316): 1152–1155. Bibcode:2016Sci...354.1152T. doi:10.1126/science.aag3145. PMID 27934766. S2CID 45815137.

External links

  • Valine MS Spectrum
  • Isoleucine and valine biosynthesis
  • Valine's relationship to prions

January 12, 2023
valine, symbol, amino, acid, that, used, biosynthesis, proteins, contains, amino, group, which, protonated, form, under, biological, conditions, carboxylic, acid, group, which, deprotonated, form, under, biological, conditions, side, chain, isopropyl, group, m. Valine symbol Val or V 4 is an a amino acid that is used in the biosynthesis of proteins It contains an a amino group which is in the protonated NH3 form under biological conditions an a carboxylic acid group which is in the deprotonated COO form under biological conditions and a side chain isopropyl group making it a non polar aliphatic amino acid It is essential in humans meaning the body cannot synthesize it it must be obtained from the diet Human dietary sources are foods that contain protein such as meats dairy products soy products beans and legumes It is encoded by all codons starting with GU GUU GUC GUA and GUG Valine Skeletal formula of neutral valine Zwitterionic valineBall and stick model Space filling modelNamesIUPAC name ValineOther names 2 Amino 3 methylbutanoic acidIdentifiersCAS Number L 72 18 4 YD L 516 06 3 YD 640 68 6 Y3D model JSmol L Interactive imageL Zwitterion Interactive imageChEBI L CHEBI 16414 YChEMBL L ChEMBL43068 YChemSpider L 6050 YD L 1148 YD 64635 YDrugBank L DB00161 YECHA InfoCard 100 000 703EC Number L 200 773 6IUPHAR BPS L 4794KEGG L D00039 YPubChem CID L 6287D L 1182D 71563UNII L HG18B9YRS7 YD L 4CA13A832H YD Y14I1443UR YCompTox Dashboard EPA L DTXSID40883233InChI InChI 1S C5H11NO2 c1 3 2 4 6 5 7 8 h3 4H 6H2 1 2H3 H 7 8 t4 m0 s1 YKey KZSNJWFQEVHDMF BYPYZUCNSA N YD L Key KZSNJWFQEVHDMF UHFFFAOYSA ND Key KZSNJWFQEVHDMF SCSAIBSYSA NSMILES L CC C C H C O O NL Zwitterion CC C C H C O O NH3 Properties 3 Chemical formula C 5H 11N O 2Molar mass 117 148 g mol 1Density 1 316 g cm3Melting point 298 C 568 F 571 K decomposition Solubility in water soluble 85 g L 1 Acidity pKa 2 32 carboxyl 9 62 amino 2 Magnetic susceptibility x 74 3 10 6 cm3 molSupplementary data pageValine data page Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Infobox references Contents 1 History and etymology 2 Nomenclature 3 Metabolism 3 1 Source and biosynthesis 3 2 Degradation 4 Synthesis 5 Medical significance 5 1 Insulin resistance 5 2 Hematopoietic stem cells 6 See also 7 References 8 External linksHistory and etymology EditValine was first isolated from casein in 1901 by Hermann Emil Fischer 5 The name valine comes from valeric acid which in turn is named after the plant valerian due to the presence of the acid in the roots of the plant 6 7 Nomenclature EditAccording to IUPAC carbon atoms forming valine are numbered sequentially starting from 1 denoting the carboxyl carbon whereas 4 and 4 denote the two terminal methyl carbons 8 Metabolism EditSource and biosynthesis Edit Valine like other branched chain amino acids is synthesized by plants but not by animals 9 It is therefore an essential amino acid in animals and needs to be present in the diet Adult humans require about 24 mg kg body weight daily 10 It is synthesized in plants and bacteria via several steps starting from pyruvic acid The initial part of the pathway also leads to leucine The intermediate a ketoisovalerate undergoes reductive amination with glutamate Enzymes involved in this biosynthesis include 11 Acetolactate synthase also known as acetohydroxy acid synthase Acetohydroxy acid isomeroreductase Dihydroxyacid dehydratase Valine aminotransferaseDegradation Edit Like other branched chain amino acids the catabolism of valine starts with the removal of the amino group by transamination giving alpha ketoisovalerate an alpha keto acid which is converted to isobutyryl CoA through oxidative decarboxylation by the branched chain a ketoacid dehydrogenase complex 12 This is further oxidised and rearranged to succinyl CoA which can enter the citric acid cycle Synthesis EditRacemic valine can be synthesized by bromination of isovaleric acid followed by amination of the a bromo derivative 13 HO2CCH2CH CH3 2 Br2 HO2CCHBrCH CH3 2 HBr HO2CCHBrCH CH3 2 2 NH3 HO2CCH NH2 CH CH3 2 NH4BrMedical significance EditInsulin resistance Edit Lower levels of serum valine like other branched chain amino acids are associated with weight loss and decreased insulin resistance higher levels of valine are observed in the blood of diabetic mice rats and humans 14 Mice fed a BCAA deprived diet for one day had improved insulin sensitivity and feeding of a valine deprived diet for one week significantly decreases blood glucose levels 15 In diet induced obese and insulin resistant mice a diet with decreased levels of valine and the other branched chain amino acids resulted in a rapid reversal of the adiposity and an improvement in glucose level control 16 The valine catabolite 3 hydroxyisobutyrate promotes insulin resistance in mice by stimulating fatty acid uptake into muscle and lipid accumulation 17 In mice a BCAA restricted diet decreased fasting blood glucose levels and improved body composition 18 Hematopoietic stem cells Edit Dietary valine is essential for hematopoietic stem cell HSC self renewal as demonstrated by experiments in mice 19 Dietary valine restriction selectively depletes long term repopulating HSC in mouse bone marrow Successful stem cell transplantation was achieved in mice without irradiation after 3 weeks on a valine restricted diet Long term survival of the transplanted mice was achieved when valine was returned to the diet gradually over a 2 week period to avoid refeeding syndrome See also EditValinolReferences Edit Physicochemical Information emdmillipore 2022 Retrieved 17 November 2022 a href Template Cite web html title Template Cite web cite web a CS1 maint url status link Dawson RM Elliott DC Elliott WH Jones KM eds 1959 Data for Biochemical Research Oxford Clarendon Press ASIN B000S6TFHA OCLC 859821178 Weast RC ed 1981 CRC Handbook of Chemistry and Physics 62nd ed Boca Raton FL CRC Press p C 569 ISBN 0 8493 0462 8 Nomenclature and Symbolism for Amino Acids and Peptides IUPAC IUB Joint Commission on Biochemical Nomenclature 1983 Archived from the original on 9 October 2008 Retrieved 5 March 2018 Valine Encyclopaedia Britannica Online Retrieved 6 December 2015 Valine Merriam Webster Online Dictionary Retrieved 6 December 2015 Valeric acid Merriam Webster Online Dictionary Retrieved 6 December 2015 Jones JH ed 1985 Amino Acids Peptides and Proteins Specialist Periodical Reports Vol 16 London Royal Society of Chemistry p 389 ISBN 978 0 85186 144 9 Basuchaudhuri P 2016 Nitrogen metabolism in rice Boca Raton Florida CRC Press p 159 ISBN 978 1 4987 4668 7 OCLC 945482059 Institute of Medicine 2002 Protein and Amino Acids Dietary Reference Intakes for Energy Carbohydrates Fiber Fat Fatty Acids Cholesterol Protein and Amino Acids Washington DC The National Academies Press pp 589 768 doi 10 17226 10490 ISBN 978 0 309 08537 3 Lehninger Albert L Nelson David L Cox Michael M 2000 Principles of Biochemistry 3rd ed New York W H Freeman ISBN 1 57259 153 6 Mathews CK 2000 Biochemistry Van Holde K E Ahern Kevin G 3rd ed San Francisco Calif Benjamin Cummings p 776 ISBN 978 0 8053 3066 3 OCLC 42290721 Marvel CS 1940 dl Valine Organic Syntheses 20 106 Collective Volume vol 3 p 848 Lynch CJ Adams SH December 2014 Branched chain amino acids in metabolic signalling and insulin resistance Nature Reviews Endocrinology 10 12 723 36 doi 10 1038 nrendo 2014 171 PMC 4424797 PMID 25287287 Xiao F Yu J Guo Y Deng J Li K Du Y et al June 2014 Effects of individual branched chain amino acids deprivation on insulin sensitivity and glucose metabolism in mice Metabolism 63 6 841 50 doi 10 1016 j metabol 2014 03 006 PMID 24684822 Cummings NE Williams EM Kasza I Konon EN Schaid MD Schmidt BA et al February 2018 Restoration of metabolic health by decreased consumption of branched chain amino acids The Journal of Physiology 596 4 623 645 doi 10 1113 JP275075 PMC 5813603 PMID 29266268 Jang C Oh SF Wada S Rowe GC Liu L Chan MC et al April 2016 A branched chain amino acid metabolite drives vascular fatty acid transport and causes insulin resistance Nature Medicine 22 4 421 6 doi 10 1038 nm 4057 PMC 4949205 PMID 26950361 Fontana L Cummings NE Arriola Apelo SI Neuman JC Kasza I Schmidt BA et al July 2016 Decreased Consumption of Branched Chain Amino Acids Improves Metabolic Health Cell Reports 16 2 520 530 doi 10 1016 j celrep 2016 05 092 PMC 4947548 PMID 27346343 Taya Y Ota Y Wilkinson AC Kanazawa A Watarai H Kasai M et al December 2016 Depleting dietary valine permits nonmyeloablative mouse hematopoietic stem cell transplantation Science 354 6316 1152 1155 Bibcode 2016Sci 354 1152T doi 10 1126 science aag3145 PMID 27934766 S2CID 45815137 External links EditValine MS Spectrum Isoleucine and valine biosynthesis Valine s relationship to prions Retrieved from https en wikipedia org w index php title Valine amp oldid 1131366050, wikipedia, wiki, book, books, library,

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