Pathway maps

Beta-alanine metabolism
Beta-alanine metabolism

Object List (links open in MetaCore):

CPGL2, GAD1, DPYD, GAD2,, N-Carbomoyl- beta-alanine,, Carnosine,, BUP1,, S-adenosyl-(L)-methionine,, beta-Alanine, 2-Oxo-glutaric acid, Anserine, CSAD, L-Histidine, 3-Aminopropanal, ABP1, Uracyl, ALD9A1,, Malonic semialdehyde, DPYS, S-Adenosyl- (L)-homocysteine,,,,, (L)-Aspartic acid,, GABT, 1,3-Diamino propane, 5,6-Dihydrouracil


Beta-alanine metabolism.

Beta-Alanine is the only naturally occurring non-essential beta amino acid. It is formed in organism by different metabolic pathways.

One occurs via reductive pyrimidine degradation and begins with the conversion of Uracil to 5,6-Dihydrouracil by Dihydropyrimidine dehydrogenase ( DPYD ) [1], [2]. Then Dihydropyrimidinase ( DPYS ) catalyzes the reversible hydrolytic ring opening of dihydrouracil to N-Carbamoyl-beta-alanine [3], which in turn is hydrolyzed to beta-Alanine by Ureidopropionase, beta ( BUP1 ) [4], [5].

Another main pathway of beta-Alanine biosynthesis is degradation of beta-Alanyl-(L)-histidine. Carnosine N-methyltransferase (EC ) converts beta-Alanyl-(L)-histidine to Anserine using S-Adenosyl-L-methionine as methyl donor [6]. Then Anserine is hydrolyzed to beta-Alanine by Carnosine dipeptidase 1 (metallopeptidase M20 family) CPGL2 [7]. Beta-Alanyl-(L)-histidine may also be hydrolyzed by CPGL2 to beta-Alanine and (L)-Histidine [7], [8].

(L)-Aspartic acid undergoes decarboxylation to beta-Alanine by Glutamate decarboxylase 1 (brain, 67kDa) ( GAD1 ) and Glutamate decarboxylase 2 (pancreatic islets and brain, 65kDa) ( GAD2 ) [9] or by Cysteine sulfinic acid decarboxylase ( CSAD ) [10].

1, 3-Diaminopropane is involved in the beta-Alanine metabolic pathway via formation of 3-Aminopropanal by Amiloride binding protein 1 (amine oxidase (copper-containing)) ( ABP1 ) [11] followed by Aldehyde dehydrogenase 9 family, member A1 ( ALD9A1 )-catalyzed oxidation to beta- Alanine [12], [13].

4-Aminobutyrate aminotransferase ( GABT ) catalyzes the conversion of 2-Oxo-glutaric acid and beta-Alanine to L-Glutamic acid and Malonic semialdehyde that takes part in propionate metabolism [14], [15].


  1. Lu ZH, Zhang R, Diasio RB
    Purification and characterization of dihydropyrimidine dehydrogenase from human liver. The Journal of biological chemistry 1992 Aug 25;267(24):17102-9
  2. Yokota H, Fernandez-Salguero P, Furuya H, Lin K, McBride OW, Podschun B, Schnackerz KD, Gonzalez FJ
    cDNA cloning and chromosome mapping of human dihydropyrimidine dehydrogenase, an enzyme associated with 5-fluorouracil toxicity and congenital thymine uraciluria. The Journal of biological chemistry 1994 Sep 16;269(37):23192-6
  3. Kikugawa M, Kaneko M, Fujimoto-Sakata S, Maeda M, Kawasaki K, Takagi T, Tamaki N
    Purification, characterization and inhibition of dihydropyrimidinase from rat liver. European journal of biochemistry / FEBS 1994 Jan 15;219(1-2):393-9
  4. Matthews MM, Liao W, Kvalnes-Krick KL, Traut TW
    beta-Alanine synthase: purification and allosteric properties. Archives of biochemistry and biophysics 1992 Mar;293(2):254-63
  5. Sakamoto T, Sakata SF, Matsuda K, Horikawa Y, Tamaki N
    Expression and properties of human liver beta-ureidopropionase. Journal of nutritional science and vitaminology 2001 Apr;47(2):132-8
  6. Raghavan M, Lindberg U, Schutt C
    The use of alternative substrates in the characterization of actin-methylating and carnosine-methylating enzymes. European journal of biochemistry / FEBS 1992 Nov 15;210(1):311-8
  7. Jackson MC, Kucera CM, Lenney JF
    Purification and properties of human serum carnosinase. Clinica chimica acta; international journal of clinical chemistry 1991 Feb 15;196(2-3):193-205
  8. Teufel M, Saudek V, Ledig JP, Bernhardt A, Boularand S, Carreau A, Cairns NJ, Carter C, Cowley DJ, Duverger D, Ganzhorn AJ, Guenet C, Heintzelmann B, Laucher V, Sauvage C, Smirnova T
    Sequence identification and characterization of human carnosinase and a closely related non-specific dipeptidase. The Journal of biological chemistry 2003 Feb 21;278(8):6521-31
  9. Porter TG, Martin DL
    Non-steady-state kinetics of brain glutamate decarboxylase resulting from interconversion of the apo- and holoenzyme. Biochimica et biophysica acta 1986 Nov 21;874(2):235-44
  10. Griffith OW
    Cysteinesulfinate metabolism. altered partitioning between transamination and decarboxylation following administration of beta-methyleneaspartate. The Journal of biological chemistry 1983 Feb 10;258(3):1591-8
  11. Callery PS, Subramanyam B, Yuan ZM, Pou S, Geelhaar LA, Reynolds KA
    Isotopically sensitive regioselectivity in the oxidative deamination of a homologous series of diamines catalyzed by diamine oxidase. Chemico-biological interactions 1992 Nov 30;85(1):15-26
  12. Vaz FM, Fouchier SW, Ofman R, Sommer M, Wanders RJ
    Molecular and biochemical characterization of rat gamma-trimethylaminobutyraldehyde dehydrogenase and evidence for the involvement of human aldehyde dehydrogenase 9 in carnitine biosynthesis. The Journal of biological chemistry 2000 Mar 10;275(10):7390-4
  13. Wood PL, Khan MA, Moskal JR
    The concept of "aldehyde load" in neurodegenerative mechanisms: cytotoxicity of the polyamine degradation products hydrogen peroxide, acrolein, 3-aminopropanal, 3-acetamidopropanal and 4-aminobutanal in a retinal ganglion cell line. Brain research 2007 May 11;1145:150-6
  14. Schousboe A, Wu JY, Roberts E
    Purification and characterization of the 4-aminobutyrate--2,ketoglutarate transaminase from mouse brain. Biochemistry 1973 Jul 17;12(15):2868-73
  15. Schor DS, Struys EA, Hogema BM, Gibson KM, Jakobs C
    Development of a stable-isotope dilution assay for gamma-aminobutyric acid (GABA) transaminase in isolated leukocytes and evidence that GABA and beta-alanine transaminases are identical. Clinical chemistry 2001 Mar;47(3):525-31