Porphobilinogen

Porphobilinogen
Names
Preferred IUPAC name
3-[5-(Aminomethyl)-4-(carboxymethyl)-1H-pyrrol-3-yl]propanoic acid
Identifiers
3D model (JSmol)
ChemSpider
DrugBank
ECHA InfoCard 100.006.970 Edit this at Wikidata
EC Number
  • 207-666-3
MeSH Porphobilinogen
UNII
  • InChI=1S/C10H14N2O4/c11-4-8-7(3-10(15)16)6(5-12-8)1-2-9(13)14/h5,12H,1-4,11H2,(H,13,14)(H,15,16) checkY
    Key: QSHWIQZFGQKFMA-UHFFFAOYSA-N checkY
  • C1=C(C(=C(N1)CN)CC(=O)O)CCC(=O)O
Properties
C10H14N2O4
Molar mass 226.229
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Porphobilinogen (PBG) is an organic compound that occurs in living organisms as an intermediate in the biosynthesis of porphyrins, which include critical substances like hemoglobin and chlorophyll.[1]

The structure of the molecule can be described as molecule of pyrrole with sidechains substituted for hydrogen atoms at positions 2, 3 and 4 in the ring (1 being the nitrogen atom); respectively, an aminomethyl group −CH2−NH2, an acetic acid (carboxymethyl) group −CH2−COOH, and a propionic acid (carboxyethyl) group −CH2−CH2−COOH.

Biosynthesis

In a early step of the porphyrin biosynthesis pathway, porphobilinogen is generated from aminolevulinic acid (ALA) by the enzyme ALA dehydratase.[2]

2
 
2D representation of the chemical structure of aminolevulinic acid .
aminolevulinic acid
 
2 H2O
Rightward reaction arrow with minor product(s) to top right
 
 
 
2D representation of the chemical structure of porphobilinogen .
porphobilinogen

Metabolism

Next in the pathway towards porphyrins, four molecules of porphobilinogen are combined into hydroxymethyl bilane by the enzyme porphobilinogen deaminase:[2][3][4]

4
 
2D representation of the chemical structure of porphobilinogen .
porphobilinogen
 
H2O
4 NH3
Rightward reaction arrow with minor substrate(s) from top left and minor product(s) to top right
 
 
 
2D representation of the chemical structure of hydroxymethylbilane.
hydroxymethylbilane

Pathologies

Acute intermittent porphyria causes an increase in urinary porphobilinogen.[5]

References

  1. ^ Paul R. Ortiz de Montellano (2008). "Hemes in Biology". Wiley Encyclopedia of Chemical Biology. John Wiley & Sons. doi:10.1002/9780470048672.wecb221. ISBN 978-0470048672.
  2. ^ a b Battersby, Alan R. (2000). "Tetrapyrroles: The pigments of life". Natural Product Reports. 17 (6): 507–526. doi:10.1039/B002635M. PMID 11152419.
  3. ^ Voet, Donald; Voet, Judith G. (2011). Biochemistry (4. ed.). Hoboken, NJ: Wiley. ISBN 978-0-470-57095-1.
  4. ^ Enzyme 2.5.1.61 at KEGG Pathway Database.
  5. ^ Aarsand, AK; Petersen PH; Sandberg S (April 2006). "Estimation and application of biological variation of urinary delta-aminolevulinic acid and porphobilinogen in healthy individuals and in patients with acute intermittent porphyria". Clinical Chemistry. 52 (4): 650–656. doi:10.1373/clinchem.2005.060772. PMID 16595824.
allikas: https://en.wikipedia.org/wiki/Porphobilinogen