Formation of a Membrane Potential by Reconstituted Liposomes Made with Cytochrome b562-o Complex, a Terminal Oxidase of Escherichia coli*

作者：Kiyoshi Kita, Masahiro Kasahara, Yasuhiro Anraku · 发表于：Journal of Biological Chemistry · 年份：1982 · DOI：10.1016/s0021-9258(18)34273-x · 被引用次数：93 · 研究领域：Lipid Membrane Structure and Behavior、Photosynthetic Processes and Mechanisms、Molecular Sensors and Ion Detection

A terminal oxidase of the Escherichia coli K12 respiratory chain (cytochrome b562-o complex) was reconstituted into liposomes by freeze-thaw/sonication method. Formation of a membrane potential (-145 mV) by the reconstituted cytochrome b562-o complex was observed with the fluorescent dye 3,3'-dipropylthiodicarbocyanine iodide on addition of an artificial electron donor ubiquinol-1 or ascorbate-phenazine methosulfate. The membrane potential formed was inhibited by the protonophore uncouplers 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile, carbonyl cyanide p-trifluoromethoxyphenylhydrazone, and carbonylcyanide m-chlorophenylhydrazone, and the inhibitors of the oxidase system zinc sulfate, potassium cyanide, and 2-n-heptyl-4-hydroxyquinoline-N-oxide. This is the first indication that there is a coupling site in an E. coli terminal oxidase, which consists of b-type cytochromes.