Quinone-independent reduction of cytochrome b-1 by reduced nicotinamide adenine dinucleotide in a purified soluble system from Escherichia coli.
Abstract
Receive: RSS Feeds, eTOCs, free email alerts (when new articles cite this article), more» Information about commercial reprint orders: http://jb.asm.org/site/misc/reprints.xhtml To subscribe to to another ASM Journal go to: http://journals.asm.org/site/subscriptions/ JOURNAL OF BACTERIOLOGY, Nov., 1965 Copyright © 1965 American Society for Microbiology Vol. 90, No. 5 Printed in U.S.A. Department of P. D. BRAGG Biochemistry, University of British Columbia, Vancouver, British Columbia, Canada Downloaded from http://jb.asm.org/ on December 9, 2011 by deepdyve Received for publication 2 July 1965 Oxidation of reduced nicotinamide adenine dinucleotide (NADH2) coupled to the cytochrome chain of Escherichia coli appears to involve the lipoquinones, vitamin K2, and coenzyme Q8 [Kashket and Brodie, J. Biol. Chem. 238:2564, 1963; Itagaki, J. Biochem. (Tokyo) 55:432, 1964]. However, in contrast to this, menadione reductase (NADH2-2-methyl-1 ,4-naphthoquinone oxidoreductase) solubilized and purified from particles of E. coli, although showing high activity in naphthoquinone reduction, will couple the oxidation of NADH2 to the reduction of a purified soluble preparation of E. coli cytochrome b1 without the addition of lipoquinone. This note describes the properties of this system which, in its nonrequirement for quinone, resembles the formate dehydrogenase-cytochrome bi complex isolated from E. coli by Linnane and Wrigley (Biochim. Biophys. Acta 77:408,