NADH/NAD+ interaction with NADH: Ubiquinone oxidoreductase (complex I)

3D Reconstruction of a Subcomplex of NADH-ubiquinone-oxidoreductase (Complex I) from Yarrowia lipolytica.

Complex I is the first and largest enzyme in the respiratory chain located in the inner mitochondrial membrane and in the membrane of many bacteria [1]. In the process of oxidizing NADH, Complex I translocates 4 protons across the membrane. This is followed by additional proton translocation by complexes III and IV. The resulting membrane potential powers ATP production by the F-ATPase. The min...

Diphenyleneiodonium inhibits reduction of iron-sulfur clusters in the mitochondrial NADH-ubiquinone oxidoreductase (Complex I).

Diphenyleneiodonium (DPI) inhibits the mitochondrial NADH-ubiquinone oxidoreductase (Complex I) on the substrate side of the Fe-S clusters. In the inhibited NADH-supplemented state all of the Fe-S clusters are oxidized, whereas the reduced minus oxidized difference spectrum of the protein-bound FMN can be visualized. It is characterized by troughs at 370 and 450 nm and a small increase of absor...

Electron and Proton Transfer in NADH: Ubiquinone Oxidoreductase (Complex I) from Escherichia coli

Direct interaction between yeast NADH-ubiquinone oxidoreductase, succinate-ubiquinone oxidoreductase, and ubiquinol-cytochrome c oxidoreductase in the reduction of exogenous quinones.

The reduction of the following exogenous quinones by succinate and NADH was studied in mitochondria isolated from both wild type and ubiquinone (Q)-deficient strains of yeast: ubiquinone-0 (Q0), ubiquinone-1 (Q1), ubiquinone-2 (Q2), and its decyl analogue 2,3-dimethoxy-5-methyl-6-decyl-1,4-benzoquinone (DB), duroquinone (DQ), menadione (MQ), vitamin K1 (2-methyl-3-phytyl-1,4-naphthoquinone), th...

Origin and Evolution of the Sodium -Pumping NADH: Ubiquinone Oxidoreductase

The sodium -pumping NADH: ubiquinone oxidoreductase (Na+-NQR) is the main ion pump and the primary entry site for electrons into the respiratory chain of many different types of pathogenic bacteria. This enzymatic complex creates a transmembrane gradient of sodium that is used by the cell to sustain ionic homeostasis, nutrient transport, ATP synthesis, flagellum rotation and other essential pro...