uroporphyrinogen

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uroporphyrinogen

 [u″ro-por″fĭ-rin´o-jen]
a porphyrinogen formed from porphobilinogen; it is a precursor of uroporphyrin and coproporphyrinogen.

por·phy·rin·o·gens

(pōr'fi-rin'ō-jenz),
Intermediates in the biosynthesis of heme, as follows: four porphobilinogens condense to form uroporphyrinogens I and III (giving rise to side products uroporphyrins I and III) that are decarboxylated to form coproporphyrinogens I and III (giving rise to side products coproporphyrins I and III); coproporphyrinogen III is oxidized to protoporphyrinogen III (IX), which is then oxidized to form protoporphyrin III (IX) (this last intermediate adds ferrous iron to yield heme); certain porphyrinogens are elevated in certain porphyrias.

por·phy·rin·o·gens

(pōr'fir-in'ō-jenz)
Intermediates in the biosynthesis of heme; certain porphyrinogens are elevated in certain porphyrias.
References in periodicals archive ?
It is an autosomal recessive disorder, which results from deficiency of enzyme uroporphyrinogen III cosynthase (or uroporphyrinogen III synthase).
It is caused by deficient uroporphyrinogen III synthase (URO-III-synthase), the fourth enzyme in the heme biosynthetic pathway.
Further researches on the characteristics of chlorophyll metabolism indicated that the precursors of D-aminolevulinic acid (ALA), porphobilinogen (PBG), uroporphyrinogen III (Urogen III), coproporphyrinogen III (Coprogen III), protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg-Proto IX) and protochlorophyllide (Pchlide) in chlorophyll biosynthesis in Burley21 were lower than in Maryland609 at vigorous growing period; the activity of D-aminolevulinate dehydratase (ALAD) in Burley21 was 0.43% as compared to Maryland609, but the activity of chlorophyllase in Burley21 was 2.04 times as high as in that of Maryland609.
Chlorophyll biosynthesis in higher plants was carried and accomplished by sequential reactions, D-aminolevulinic acid (ALA), porphobilinogen (PBG), uroporphyrinogen III (Urogen III), coproporphyrinogen III (Coprogen III), protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg- Proto IX) and protochlorophyllide (Pchlide) were the major synthetic precursors during these sequential reactions (Ilag et al., 1994; Nagata et al., 2005; Shi et al., 2009).
In both the classical and the alternative pathway, 5-aminolevulinic acid (ALA) serves as the common precursor for heme formation which is converted into the biosynthetic intermediate uroporphyrinogen III (UROGEN) in three consecutive enzymatic steps.
barkeri the two enzymes which consecutively convert uroporphyrinogen III into sirohydrochlorin [3] and the three enzymes which convert siroheme into heme (this study) were biochemically characterized.
[1,2] Primary abnormality in CEP is due to decreased uroporphyrinogen III cosynthase activity resulting in accumulation and hyperexcretion of biologically inactive type I porphyrins.
Congenital erythropoietic porphyria, also known as Gunther disease, is one of the first inborn errors of metabolisms to be described.3 This autosomal recessive disorder is caused by deficient activity of uroporphyrinogen III synthase (URO IIIs)/ uroporphyrinogen cosynthase in the erythrocyte precursor cells.
In EP, a deficient activity of the enzyme uroporphyrinogen III synthase in erythrocyte precursor cells results in overproduction of isomer I porphyrinogens that cannot be used to form heme.
Chlorophyll biosynthesis in higher plants was carried and accomplished by sequential reactions, d-aminolevulinic acid (ALA), porphobilinogen (PBG), uroporphyrinogen III (Urogen III), coproporphyrinogen III (Coprogen III), protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg-Proto IX) and protochlorophyllide (Pchlide) were the major synthetic precursors during these sequential reactions (Ilag et al., 1994; Nagata et al., 2005; Shi et al., 2009).
This is closed by uroporphyrinogen III synthase to form uroporphyrinogen III or, alternatively, nonenzymatically to form uroporphyrinogen I.
Coexistence of deficiencies of uroporphyrinogen III synthase and decarboxylase in a patient with congenital erythropoietic porphyria and in his family.