This report suggests an important physiological role of a CYP in the accumulation of uroporphyrin I arising from catalytic oxidative conversion of uroporphyrinogen I to uroporphyrin I in the periplasm of Escherichia coli cultured in the presence of 5-aminolevulinic acid. A structurally competent Streptomyces griseus CYP105D1 was expressed as an engineered, exportable form in aerobically grown E...

Porphyria cutanea tarda (PCT) is characterized biochemically by excessive hepatic synthesis and urinary excretion of uroporphyrin I. Clinical evidence has implicated iron in the pathogenesis of PCT. The synthesis of the normally occurring isomer of uroporphyrin, namely uroporphyrin III, from porphobilinogen (PBG) requires two enzymes; uroporphyrinogen I synthetase and uroporphyrinogen III cosyn...

Cultures of chick-embryo hepatocytes were used to study the mechanism by which 3,4,3',4'-tetrachlorobiphenyl and 2,4,5,3',4'-pentabromobiphenyl cause accumulation of uroporphyrin. In a previous paper, an isoenzyme of cytochrome P-450 induced by 3-methylcholanthrene had been implicated in this process [Sinclair, Bement, Bonkovsky & Sinclair (1984) Biochem. J. 222, 737-748]. Cells treated with 3,...

Porphyria cutanea tarda and erythropoietic porphyria are disorders of heme synthesis that originate in the liver and bone marrow, respectively. Each is characterized by increased accumulation of uroporphyrin, I, by cutaneous photosensitivity, and in some patients by indurated plaques and scarring that resemble scleroderma. These scleroderma-like lesions occur in light-exposed and light-protecte...

The relationship between hepatic uroporphyrin accumulation and uroporphyrinogen decarboxylase (EC 4.1.1.37) activity was investigated in cultured chick-embryo hepatocytes, Japanese quail (Coturnix coturnix japonica) and mice that had been treated with polyhalogenated aromatic compounds. Chick-embryo hepatocytes treated with 3,3',4,4'-tetrachlorobiphenyl accumulated uroporphyrin in a dose-depend...

5. Specimens from Prof. C. J. Watson's laboratory have been examined. The uroporphyrin methyl ester I had m.p. 292-293° and behaved as uroporphyrin I containing a trace of uroporphyrin III on paper chromatography. The 2080 ester behaved chromatographically as a hexacarboxylic porphyrin. We wish to thank Dr Falk and Miss Benson for performing the chromatographic examinations by their method, and...

UNLABELLED Hexachlorobenzene-induced porphyria is iron dependent and characterized by the decreased activity of uroporphyrinogen decarboxylase and the accumulation of porphyrins in the liver. To examine the relationship between iron and porphyrins in liver tissue, we performed a biochemical and morphological (histological, ultrastructural and morphometrical) study in the livers of C57BL/10 mice...

A simple routine method for the separation and quantification of urinary coproporphyrin and uroporphyrin using anion-exchange resin columns is described. The coproporphyrin is first removed from the urine by ether extraction. The anion exchange resin column is then used to isolate the uroporphyrin from the aqueous residue. The proposed method is compared with an existing method developed by Rim...

Intravenous administration of hematin is effective in the treatment of acute exacerbations of the inducible porphyrias. In the course of such treatment, coagulopathies have occurred that are characterized by prolongation of prothrombin time, partial thromboplastin time, and formation of fibrin split products. In experiments in vitro with normal human plasma, we observed that hematin and protopo...