The EPR spectra of the NO complexes of frozen solutions of ascorbic acid-reduced cytochrome oxidase (nitrite reductase) purified from Pseudomonas aeruginosa, of its heme d1-depleted form, and of heme d1 in solutions containing various nitrogenous bases are quite similar to each other as well as to several heme (iron protoporphyrin IX)-containing proteins. The NO complexes of heme d1 (an iron-ch...

The Ehrlich ascites tumor takes up intravenous Fe 59 and utilizes much of this for cellular heme formation. In vivo experiments showed tha t the amount of iron utilized by liver and marrow for heme synthesis was directly related to the amount of iron taken up by these tissues. In vitro experiments revealed no difference in iron-protoporphyrin chelation by liver mitochondria from control and tum...

Bordetella pertussis and Bordetella bronchiseptica are capable of obtaining iron from hemin and hemoglobin. Genes encoding a putative bacterial heme iron acquisition system (bhu, for Bordetella heme utilization) were identified in a B. pertussis genomic sequence database, and the corresponding DNA was isolated from a virulent strain of B. pertussis. A B. pertussis bhuR mutant, predicted to lack...

Heme, is a cofactor for essential proteins, it is synthesized after the insertion of Fe2+ into protoporphyrin ring by the ferrochelatase (FC) enzyme. Although FC is well described, there are still major questions about the regulation of the heme biosynthetic pathway, and the localization of the enzyme in plants. This review provides a comprehensive survey of research on function and the metabol...

Cystic fibrosis (CF) patients suffer from chronic bacterial lung infections, most notably by Pseudomonas aeruginosa, which persists for decades in the lungs and undergoes extensive evolution. P. aeruginosa requires iron for virulence and uses the fluorescent siderophore pyoverdine to scavenge and solubilize ferric iron during acute infections. Pyoverdine mutants accumulate in the lungs of some ...

Heme is of significant importance in iron nutrition and in systemic iron metabolism. The crux of the matter is that while much is known about non-heme metabolism, the vectorial import of exogenous porphyrin macromolecules into the enterocyte and possibly into blood circulation is still speculative. The inhibitory effect of calcium on heme iron absorption has been previously reported in the lite...

Heme formation in reticulocytes from rabbits and rodents is subject to end product negative feedback regulation: intracellular “free” heme has been shown to control acquisition of transferrin iron for heme synthesis. To identify the site of control of heme biosynthesis in the human erythron, immature erythroid cells were obtained from peripheral blood and aspirated bone marrow. After incubation...

Zinc protoporphyrin (ZnPP) is a normal metabolite that is formed in trace amounts during heme biosynthesis. The final reaction in the biosynthetic pathway of heme is the chelation of iron with protoporphyrin. During periods of iron insufficiency or impaired iron utilization, zinc becomes an alternative metal substrate for ferrochelatase, leading to increased ZnPP formation. Evidence suggests th...

In the study presented here, the iron status in the kidney in passive Heymann nephritis, a complement-dependent model of membranous nephropathy, was examined. To examine whether the effect of immune injury on iron status has a pathogenic role, the effect of an iron-deficient diet was also determined. Injection of the anti-Fx1A antibody (10 mg/100 g body wt) in Sprague-Dawley rats resulted in no...