NADH-ascorbate free radical and -ferricyanide reductase activities represent different levels of plasma membrane electron transport

• Published in: Journal of bioenergetics and biomembranes Vol. 25; no. 4; p. 411
• Main Authors: Villalba, J M, Canalejo, A, Rodríguez-Aguilera, J C, Burón, M I, Mooré, D J, Navas, P
• Format: Journal Article
• Language: English
• Published: United States 01.08.1993
• Subjects: Animals; Cholic Acids; Coated Pits, Cell-Membrane - enzymology; Electron Transport; Electrophoresis, Polyacrylamide Gel; Free Radicals; Liver - enzymology; Liver - ultrastructure; Membrane Proteins - isolation & purification; Membrane Proteins - metabolism; NADH Dehydrogenase - metabolism; NADH, NADPH Oxidoreductases - antagonists & inhibitors; NADH, NADPH Oxidoreductases - isolation & purification; NADH, NADPH Oxidoreductases - metabolism; Oxidation-Reduction; Rats; Rats, Wistar; Wheat Germ Agglutinins - pharmacology
• ISSN: 0145-479X
• DOI: 10.1007/BF00762467

Plasma membranes isolated from rat liver by two-phase partition exhibited dehydrogenase activities for ascorbate free radical (AFR) and ferricyanide reduction in a ratio of specific activities of 1:40. NADH-AFR reductase could not be solubilized by detergents from plasma membrane fractions. NADH-AFR reductase was inhibited in both clathrin-depleted membrane and membranes incubated with anti-clathrin antiserum. This activity was reconstituted in plasma membranes in proportion to the amount of clathrin-enriched supernatant added. NADH ferricyanide reductase was unaffected by both clathrin-depletion and antibody incubation and was fully solubilized by detergents. Also, wheat germ agglutinin only inhibited NADH-AFR reductase. The findings suggest that NADH-AFR reductase and NADH-ferricyanide reductase activities of plasma membrane represent different levels of the electron transport chain. The inability of the NADH-AFR reductase to survive detergent solubilization might indicate the involvement of more than one protein in the electron transport from NADH to the AFR but not to ferricyanide.