porphobilinogen

porphobilinogen
A porphyrin precursor of porphyrinogens, porphyrins, and heme; found in the urine in large quantities in cases of acute or congenital porphyria.
- p. synthase a liver enzyme catalyzing the formation of p. and water from two molecules of δ-aminolevulinate, an important reaction in porphyrin biosynthesis; inhibited by lead in cases of lead poisoning; a deficiency of this enzyme results in elevated levels of δ-aminolevulinate and results in neurologic disturbances. SYN: δ-aminolevulinate dehydratase.

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por·pho·bi·lin·o·gen .pȯr-fō-bī-'lin-ə-jən n a dicarboxylic acid C10H14N2O4 that is derived from pyrrole, that is found in the urine in acute porphyria, and that on condensation of four molecules yields uroporphyrin and other porphyrins

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n.
a pigment that appears in the urine of individuals with acute porphyria, causing it to darken if left standing.

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por·pho·bi·lin·o·gen (por″fo-bĭ-linґə-jən) the immediate precursor of the porphyrins, a pyrrole ring with acetyl, propionyl, and aminomethyl side chains; four molecules of porphobilinogen are condensed to form one molecule of uroporphyrinogen III, which is then converted successively to coproporphyrinogen III, protoporphyrin IX, and heme. Porphobilinogen is produced in excess and excreted in the urine in acute intermittent porphyria and several other porphyrias. Abbreviated PBG.

Medical dictionary. 2011.

Look at other dictionaries:

  • porphobilinogen — noun ( s) Etymology: probably from porphyrin + o + bili + in + o + gen : a dicarboxylic acid H2NCH2(C4H2N)(CH2COOH)CH2CH2COOH that is derived from pyrrole and formed from two molecules of delta amino levulinic acid, that is found in the urine in… …   Useful english dictionary

  • Porphobilinogen — Strukturformel Allgemeines Name Porphobilinogen Andere Namen …   Deutsch Wikipedia

  • Porphobilinogen — Chembox new ImageFile= Porphobilinogen.png ImageSize=200px IUPACName=3 [5 (Aminomethyl) 4 (carboxymethyl) 1H pyrrol 3 yl] propanoic acid OtherNames= Section1= Chembox Identifiers CASNo=487 90 1 PubChem=1021 SMILES=C1=C(C(=C(N1)CN)CC(=O)O)CCC(=O)O …   Wikipedia

  • porphobilinogen — noun A pyrrole involved in porphyrin metabolism, generated by aminolevulinate and the enzyme ALA dehydratase. Syn: PBG …   Wiktionary

  • porphobilinogen — n. a pigment that appears in the urine of individuals with acute porphyria, causing it to darken if left standing …   The new mediacal dictionary

  • Porphobilinogen deaminase — (or hydroxymethylbilane synthase) is an enzyme involved in the third step of the metabolism of porphyrin, converting porphobilinogen into hydroxymethyl bilane. The enzyme has the unique cofactor dipyrromethane. Defective activity of this enzyme… …   Wikipedia

  • Porphobilinogen synthase — Identifiers EC number 4.2.1.24 CAS number 9036 37 7 …   Wikipedia

  • Porphobilinogen-Desaminase — Vorhandene Strukturdaten …   Deutsch Wikipedia

  • Porphobilinogen-Synthase — Δ Aminolävulinsäure Dehydratase Vorhandene Strukturdaten: 1E51 …   Deutsch Wikipedia

  • porphobilinogen synthase — por·pho·bi·lin·o·gen syn·thase (por″fo bĭ linґo jən sinґthās) [EC 4.2.1.24] an enzyme of the lyase class that catalyzes the condensation of two molecules of δ aminolevulinate to form porphobilinogen in the synthesis of… …   Medical dictionary

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