Porphobilinogen

Porphobilinogen
Names
	Preferred IUPAC name 3-[5-(Aminomethyl)-4-(carboxymethyl)-1H-pyrrol-3-yl]propanoic acid
Identifiers
CAS Number	487-90-1 ;
3D model (JSmol)	Interactive image;
ChemSpider	995 ;
DrugBank	DB02272 ;
ECHA InfoCard	100.006.970
EC Number	207-666-3;
MeSH	Porphobilinogen
PubChem CID	1021;
UNII	74KHC72QXK ;
CompTox Dashboard (EPA)	DTXSID4060070 ;
	InChI 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) Key: QSHWIQZFGQKFMA-UHFFFAOYSA-N ;
	SMILES C1=C(C(=C(N1)CN)CC(=O)O)CCC(=O)O;
Properties
Chemical formula	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). Infobox references

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

2

aminolevulinic acid

2 H₂O

Rightward reaction arrow with minor product(s) to top right

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

porphobilinogen

H₂O

4 NH₃

Rightward reaction arrow with minor substrate(s) from top left and minor product(s) to top right

hydroxymethylbilane

Pathologies

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

References

^ 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.
^ ^a ^b Battersby, Alan R. (2000). "Tetrapyrroles: The pigments of life". Natural Product Reports. 17 (6): 507–526. doi:10.1039/B002635M. PMID 11152419.
^ Voet, Donald; Voet, Judith G. (2011). Biochemistry (4. ed.). Hoboken, NJ: Wiley. ISBN 978-0-470-57095-1.
^ Enzyme 2.5.1.61 at KEGG Pathway Database.
^ 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.

[Hemes-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.

[Battersby-2] 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.

[1]

[2]

[3]

[4]

[5]