1.1.5.4 FAD in absence of FAD no reduction of 2,6-dichlorophenol indophenol is observed 287734 1.1.5.4 FAD is probably a tightly but non-covalently bound prosthetic group 287733 1.1.5.4 FAD Km: 0.0004 mM 287619 1.1.5.4 FAD noncovalently bound as a prosthetic group 722575 1.1.5.4 FAD the enzyme requires FAD and vitamin K for activity 287730 1.1.5.4 FAD triple cofactor requirement for FAD, quinone and phospholipid. The formation of reduced forms of FAD is not detected, but in the presence of both FAD and phospholipid the enzyme catalyzes the reduction of quinone by L-malate at rates equivalent to the rate obtained with 2,6-dichlorophenol-indophenol as terminal acceptor. Km-value for FAD is 0.0004 mM 696072 1.1.5.4 menadione triple cofactor requirement for FAD, quinone and phospholipid. Maximum rate when phosphatidylethanolamine is added to the enzyme before the quinone 696072 1.1.5.4 menaquinone - 722575 1.1.5.4 additional information no spectral evidence for the presence of a flavin or quinone in the purified enzyme 287730 1.1.5.4 additional information the enzyme is active with 2,6-dichlorophenolindophenol 723124 1.1.5.4 additional information the enzymeis active with duroquinone and dimethyl naphthoquinone 722575 1.1.5.4 ubiquinone - 722575, 723124 1.1.5.4 ubiquinone-0 triple cofactor requirement for FAD, quinone and phospholipid. Maximum activation rate when phosphatidylethanolamine is added to the enzyme before the quinone 696072 1.1.5.4 ubiquinone-1 the route of electrons in this assay is unclear, but it probably leads from the enzyme either directly or via quinones to 2,6-dichlorophenol indophenol. The malate-dependent 2,6-dichlorophenol indophenol reduction rate catalyzed by Helicobacter pylori membranes could be stimulated by 30 to 50% by the addition of 60 mM ubiquinone-1. This suggests that quinones play, at least in part, an intermediary role in the reduction of the dye 287737 1.1.5.4 ubiquinone-9 triple cofactor requirement for FAD, quinone and phospholipid. The formation of reduced forms of FAD is not detected, but in the presence of both FAD and phospholipid the enzyme catalyzes the reduction of quinone by L-malate at rates equivalent to the rate obtained with 2,6-dichlorophenol-indophenol as terminal acceptor. The quinone is identified as ubiquinone 9. Km-value for ubiquinone 9 is 0.0024 mM 696072 1.1.5.4 vitamin K1 the enzyme requires FAD and vitamin K for activity 287730 1.1.5.4 vitamin K1 with both vitamin K1 and ubiquinone-9, maximum rates are obtained by exposing the enzyme to phospholipid and quinone simultaneously, but, when phosphatidylethanolamine is added to the enzyme before either of these quinones, the rates are much lower 696072