[Purification and properties of Rhodospirillum rubrum NADP-reductase].

Rhodospirillum rubrum cell extracts have active NADP-reductase capable of catalyzing the diaphorase reaction in the presence of methyl viologene or benzyl viologene and NADPH-generating system. The greater part of NADP-reductase is localized in the soluble fraction of destroyed cells (90-10(3) g; 90 min). The purified preparation of NADP-reductase was found to contain 6 proteins, 4-5 of them possessing diaphorase activity. Partially purified NADP-reductase preparation with a period of half-inactivation of about two days has a molecular weight of 95 000 and absorption spectrum, characterized by two maxima at 410 and 430 nm. NADP-reductase preparation possesses also menadione-reductase activity, but showed no ability for transhydrogenase reaction and reduction of cytochrome c.