title: Purification, properties, and cellular localization of Euglena ferredoxin-NADP reductase.
abstract: Ferredoxin-NADP reductase from Euglena gracilis Klebs var. Bacillaris Cori purified to apparent homogeneity, yields a typical 36 kDa and an unusual 15 kDa polypeptide on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, exhibits a typical flavoprotein spectrum, contains FAD, and catalyzes NADPH-dependent iodonitrotetrazolium-violet diaphorase, NADPH-specific ferredoxin-dependent cytochrome-c-550 reductase and NADPH-NAD transhydrogenase activities. Rabbit antibody to the purified FNR blocks these activities specifically and also blocks the iodonitrotetrazolium-violet diaphorase activity of Euglena chloroplast completely. The low iodonitrotetrazolium-violet diaphorase activity in the plastidless mutant, W10BSmL, is mitochondrial and is not specifically blocked by the ferredoxin-NADP reductase antibody. Dark-grown non-dividing (resting) wild-type Euglena cells show a 4-fold increase in ferredoxin-NADP reductase activity during greening at 970 lx. Half of the low ferredoxin-NADP reductase activity in dark-grown cells is initially soluble, but by the end of chloroplast development nearly all of the enzyme is membrane-bound. The binding of ferredoxin-NADP reductase on exposure to light correlates with the extent of thylakoid membrane formation. Immunoblots of wild-type extracts during greening indicate that the 15 kDa polypeptide increases in the same manner as the extent of reductase binding to thylakoid membranes.
mesh_terms: D000818:Animals; D002736:Chloroplasts / Q000201:enzymology; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D005056:Euglena gracilis / Q000201:enzymology* / Q000648:ultrastructure; D005287:Ferredoxin-NADP Reductase / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D007425:Intracellular Membranes / Q000201:enzymology; D008970:Molecular Weight; D009247:NADH, NADPH Oxidoreductases / Q000302:isolation & purification*
chemical_list: D005287:Ferredoxin-NADP Reductase; D009247:NADH, NADPH Oxidoreductases