The terminal oxidase for ethanol oxidation in Acetobacter aced was purified as a complex consisting of four subunits (subunits I, II, III, and IV) with molecular masses of 72, 34, 21, and 13 kDa, respectively. Spectrophotometric analysis and catalytic properties determined with the purified enzyme showed that it belonged to a family of cytochrome a, (ba)-type ubiquinol oxidases. A polymerase ch...

BACKGROUND Considering all the couples willing and trying to get pregnant, the incidence of infertility is 15% of which approximately half of the cases are due to the male factors. OBJECTIVES The aim of this study was the investigation of the effects of ubiquinol, reduced form of coenzyme Q10 (Co-Q10), an empiric treatment modality, on sperm parameters in idiopathic subfertility. PATIENTS A...

Bifurcated electron transfer during ubiquinol oxidation is the key reaction of cytochrome bc1 complex catalysis. Binding of the competitive inhibitor 5-n-heptyl-6-hydroxy-4,7-dioxobenzothiazole to the Qo site of the cytochrome bc1 complex from Saccharomyces cerevisiae was analyzed by x-ray crystallography. This alkylhydroxydioxobenzothiazole is bound in its ionized form as evident from the crys...

A purified, active succinate-ubiquinone reductase was prepared from succinate-cytochrome c reductase without damage to ubiquinol-cytochrome c reductase by 1.1% Triton X-100 solubilization at pH 8.0, and calcium phosphate column chromatography in 50 mM Tris-succinate buffer, pH 8.0, containing 30 mM potassium phosphate. Succinate-ubiquinone reductase thus obtained contains ubiquinone and catalyz...

Objective: Coenzyme Q10 (CoQ10) appears to be a promising agent in neurodegenerative disorders because they are associated with defects in the inner mitochondrial membrane and in oxidative phosphorylation. This report aims to highlight the role of CoQ10 in amyotrophic lateral sclerosis. Methods: A 75 year old medical scientist (1 author TK) unbiased for treatment with CoQ10, volunteered for CoQ...

In addition to its main functions of electron transfer and proton translocation, the cytochrome bc(1) complex (bc(1)) also catalyzes superoxide anion (O(2)(*)) generation upon oxidation of ubiquinol in the presence of molecular oxygen. The reaction mechanism of superoxide generation by bc(1) remains elusive. The maximum O(2)(*) generation activity is observed when the complex is inhibited by an...

Molecules of mitochondrial cardiolipin (CL) get selectively oxidized upon oxidative stress, which triggers the intrinsic apoptotic pathway. In a chemical model most closely resembling the mitochondrial membrane-liposomes of pure bovine heart CL-we compared ubiquinol-10, ubiquinol-6, and alpha-tocopherol, the most widespread naturally occurring antioxidants, with man-made, quinol-based amphiphil...