Erythropoietic protoporphyria (EPP; E80.0, ICD-10) is an inherited disorder resulting from partially deficient activity of ferrochelatase, the last enzyme in the heme biosynthetic pathway (1). In EPP, protoporphyrin accumulates in erythrocytes, bile, and skin, with photoactivation of accumulated protoporphyrin causing endothelial injury. Thus, the main symptom of EPP is painful cutaneous photos...

Nineteen male workers from a factory making lead batteries participated in monthly blood tests to follow the effects of decreasing exposures to lead. The overall average blood lead (B Pb) concentration was 1.95 mumol/l (40 micrograms/100 ml), but a significant decrease was seen over the one year study period. The relation to erythrocyte zinc-protoporphyrin (ZPP) concentration showed considerabl...

The porphyrin and phorbin biosynthetic activity of etiolated cucumber (Cucumis sativus, L.) cotyledons was compared to that of cotyledonary homogenates. Etiolated cotyledons incubated with delta-aminolevulinic acid accumulate protoporphyrin, coproporphyrin, small amounts of Mg protoporphyrin monoester, and trace amounts of uroporphyrin. They also incorporate 4-(14)C-delta-aminolevulinic acid in...

High pressure liquid chromatography was used to demonstrate that chelation of Mg(2+) into protoporphyrin IX precedes methylation in isolated greening etioplasts from cucumber (Cucumis sativus L. var. Beit Alpha) cotyledons. Mg-protoporphyrin IX synthesized in vitro from protoporphyrin IX, Mg(2+), and ATP or exogenous Mg-protoporphyrin IX could serve as substrates for the methylation step. In ei...

The effect of exogenous aminolevulinate and porphobilinogen on protoporphyrin accumulation in Rhodobacter capsulatus was measured. Oxygen inhibited protoporphyrin accumulation in strain AJB456, a bchH mutant, even in the presence of exogenous aminolevulinate, suggesting that some step in the formation of protoporphyrin from aminolevulinate is regulated by oxygen. In contrast, in the presence of...

The wide-spread occurrence of the porphyrins as constituents of many important respiratory catalysts, such as hemoglobin, the cytochromes, and catalase, attaches fundamental importance to the problem of the origin and metabolism of these substances in the organism. Progress in this field has been retarded by a lack of satisfactory methods of quantitative analysis. However, in 1943, Grinstein an...

A kinetic characterization of the regulation of purified soluble guanylate cyclase from bovine lung by protoporphyrin M and hematin is reported. Purified guanylate cyclase was isolated with heme and had specific activities @mol of cGMP/min/mg of protein) of 0.1-0.2 and 0.3-0.6 in the presence of excess MgGTP and MnGTP, respectively, in the absence of added activators. Protoporphyrin IX, nitric ...

Photoelectron spectroscopy is used to investigate the electron loss dynamics of protoporphyrin IX dianion.