Biomaterial Database

Activation of uroporphyrinogen decarboxylase by ferrous iron in porphyria cutanea tarda. 1979

G H Blekkenhorst, and L Eales, and N R Pimstone

Uroporphyrinogen decarboxylase was measured in the presence of ferrous iron, using mitochondria-free rat liver extracts as enzyme source. The activity of the enzyme was found to be increased at concentrations of ferrous iron from 0,01 mM, with maximal activity exhibited from 0,1 mM. Enzyme kinetics indicate that uroporphyrinogen decarboxylase reversibly binds ferrous iron, with a binding constant of approximately 5 x 10(4) mol-1. It is proposed that the effect of phlebotomy on patients with porphyria cutanea tarda is to mobilze storage iron in the liver to the active ferrous form, which activates hepatic uroporphyrinogen decarboxylase, the enzyme which is defective in this syndrome, with resultant clinical and biochemical remission.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D011164	Porphyrias	A diverse group of metabolic diseases characterized by errors in the biosynthetic pathway of HEME in the LIVER, the BONE MARROW, or both. They are classified by the deficiency of specific enzymes, the tissue site of enzyme defect, or the clinical features that include neurological (acute) or cutaneous (skin lesions). Porphyrias can be hereditary or acquired as a result of toxicity to the hepatic or erythropoietic marrow tissues.	Porphyria,Porphyrin Disorder,Disorder, Porphyrin,Disorders, Porphyrin,Porphyrin Disorders
D002262	Carboxy-Lyases	Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.	Carboxy-Lyase,Decarboxylase,Decarboxylases,Carboxy Lyase,Carboxy Lyases
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012871	Skin Diseases	Diseases involving the DERMIS or EPIDERMIS.	Dermatoses,Skin and Subcutaneous Tissue Disorders,Dermatosis,Skin Disease
D014575	Uroporphyrinogen Decarboxylase	An enzyme that catalyzes the decarboxylation of UROPORPHYRINOGEN III to coproporphyrinogen III by the conversion of four acetate groups to four methyl groups. It is the fifth enzyme in the 8-enzyme biosynthetic pathway of HEME. Several forms of cutaneous PORPHYRIAS are results of this enzyme deficiency as in PORPHYRIA CUTANEA TARDA; and HEPATOERYTHROPOIETIC PORPHYRIA.	Uroporphyrinogen Carboxy-Lyase,Uroporphyrinogen III Decarboxylase,Carboxy-Lyase, Uroporphyrinogen,Decarboxylase, Uroporphyrinogen,Decarboxylase, Uroporphyrinogen III,Uroporphyrinogen Carboxy Lyase
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus