Inhibitors of the transhydrogenase activity of spinach ferredoxin-Nicotinamide adenine dinucleotide phosphate reductase.
نویسندگان
چکیده
Boiled spinach extracts reversibly inhibit the transhydrogenase activity of ferredoxin-nicotinamide adenine dinucleotide phosphate reductase. The inhibition is competitive with respect to NAD but noncompetitive with respect to NADPH. The inhibitor is most effective at a pH of about 8.0. The inhibitor is characterized as an organic acid but does not appear to be a carbohydrate or phosphoric acid derivative or phosphodoxin. A number of compounds with inhibitory activity have been found. These compounds share the common chemical feature of having a vie-carbonyl gouping and include a number of cr-keto acids.
منابع مشابه
Interaction between ferredoxin and ferredoxin nicotinamide adenine dinucleotide phosphate reductase in pyridine nucleotide photoreduction and some partial reactions. I. Inhibition of ferredoxin nicotinamide adenine dinucleotide phosphate reductase by ferredoxin.
Purified ferredoxin has been shown to inhibit reactions mediated by the flavoprotein ferredoxin-NADP reductase. Ferredoxin inhibits the transfer of electrons from NADPH to ferricyanide (diaphorase activity) to NAD (transhydrogenase) and the photoreduction of pyridine nucleotides during the Hill reaction. On the basis of the kinetics of inhibition, it is suggested that the flavoprotein has two b...
متن کاملIsolation of ferredoxin-nicotinamide-adenine dinucleotide phosphate (oxidized) reductase from a prokaryote [proceedings].
The flavoprotein NADPH-ferredoxin oxidoreductase (EC 1.6.99.4) is a component of the photosynthetic electron-transport chain, catalysing the reduction of NADP+ with reduced ferredoxin (Shin et al., 1965). The enzyme also possesses activity as a NADPH diaphorase (Avron & Jagendorf, 1956), a transhydrogenase (Keister et a/., 1960) and NADPH-cytochrome f reductase (Zanetti & Forti, 1966) all three...
متن کاملGlyceraldehyde-3-phosphate dehydrogenase is regulated by ferredoxin-NADP reductase in the diatom Asterionella formosa.
Diatoms are a widespread and ecologically important group of heterokont algae that contribute c. 20% to global productivity. Previous work has shown that regulation of their key Calvin cycle enzymes differs from that of the Plantae, and that in crude extracts, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) can be inhibited by nicotinamide adenine dinucleotide phosphate reduced (NADPH) under o...
متن کاملThe Stereospecificity of the Hill Reaction with Diphosphopyridine Nucleotide.
Spinach grana cause little photoreduction of DPN unless they are supplemented with ferredoxin and TPN reductase. The latter flavoprotein catalyzes a reduction of DPN+ by TPNH, and has been termed a transhydrogenase on the basis of this reaction (2, 3). The results to be presented will show that the flavoprotein transhydrogenase reaction and the Hill reaction both involve hydrogen addition to th...
متن کاملReduction of Trimethylene Dipyridyl with Illuminated Chloroplasts.
Chloroplasts photochemically reduce 1,1'-trimethylene-2,2'-dipyridylium dibromide and concurrently form adenosine triphosphate. Reduced trimethylene dipyridyl in darkness will reduce spinach ferredoxin, Clostridium pasteurianum ferredoxin, nicotinamide-adenine dinucleotide phosphate, and other viologen-type dyes.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of biological chemistry
دوره 244 4 شماره
صفحات -
تاریخ انتشار 1969