UNLABELLED NfnAB catalyzes the reversible transfer of electrons from reduced ferredoxin and NADH to 2 NADP(+). The NfnAB complex has been hypothesized to be the main enzyme for ferredoxin oxidization in strains of Thermoanaerobacterium saccharolyticum engineered for increased ethanol production. NfnAB complex activity was detectable in crude cell extracts of T. saccharolyticum. Activity was als...

The existence of three first-order phases has been previously reported for the reduction of soluble ferredoxin by photosystem I (PSI), both from the cyanobacterium Synechocystis sp. PCC 6803 (at pH 8 and in the presence of salts) [Sétif, P. Q. Y., & Bottin, H. (1994) Biochemistry 33, 8495-8504]. The spectra of these three phases (t1/2 < 1 microsecond, = 13-20 and 103-123 microseconds) have been...

Data regarding the role of oxygen in nitrite reduction are presented. In an NADPH-generating system including homogeneously purified ferredoxin-NADP reductase, ferredoxin (or flavodoxin) and nitrite reductase from the alga Bumilleriopsis filiformis, oxygen and nitrite can be reduced simultaneously. In air, rates of 1.2 mumol nitrite reduced-min-1-mg-1 nitrite reductase are obtained, which are p...

An immunological approach, based on both antigen binding tests and radioimmunoassay, has been used for the comparative study of ferredoxin from Halobacterium of the Dead Sea and ferredoxins from a variety of sources. The halophilic ferredoxin was not cross-reactive with the plant, and the mammalian ferredoxins tested. On the other hand, it exhibited up to 80% of antigenic crossreactivity with a...

The rate of oxygen uptake of spinach ferredoxin-NADP reductase-ferredoxin complex is increased up to ZO-fold by the addition of cytochrome c. Initiation of epinephrine and sulfite oxidation indicated an involvement of the superoxide anion radical in the stimulated oxidase reaction. The final product of the reaction was shown to be Hz0 instead of HsOt, which is the product of the flavoprotein-ca...

In the malaria parasite Plasmodium falciparum isoprenoid precursors are synthesised inside a plastid-like organelle (apicoplast) by the mevalonate independent 1-deoxy-d-xylulose-5-phosphate (DOXP) pathway. The last reaction step of the DOXP pathway is catalysed by the LytB enzyme which contains a [4Fe-4S] cluster. In this study, LytB of P. falciparum was shown to be catalytically active in the ...

Ferredoxin-stimulated photosynthetic oxygen reduction and concommitant decarboxylation of glyoxylate by chloroplast lamellar systems is inhibited by ascorbate but ferredoxin dependent NADP+-reduction is not. In the presence of low potential electron acceptors (AQ or MV) this influence of ascorbate on glyoxylate decarboxylation by chloroplast lamellar systems is no longer observed. Using the dia...

Heparin, an anionic polysaccharide, inhibited the ferredoxin-catalyzed reduction of NADP in spinach chloroplast thylakoid membranes. Under the same conditions of assay, heparin did not interfere markedly with photoreduction of methyl viologen, anthraquinone sulfonate, or ferredoxin. A kinetic analysis of the heparin-induced interference with NADP photoreduction showed partial competitive inhibi...

Xanthomonas axonopodis pv. citri is a phytopathogen bacterium that causes severe citrus canker disease. Similar to other phytopathogens, after infection by this bacterium, plants trigger a defense mechanism that produces reactive oxygen species. Ferredoxin-NADP(+) reductases (FNRs) are redox flavoenzymes that participate in several metabolic functions, including the response to reactive oxygen ...