The fluorescence intensity of the lipophilic probe N‐phenyl‐1‐naphthylamine responds to the oxidation‐reduction state of purified Escherichia coli cytochrome o incorporated into phospholipid vesicles

FEBS Letters

Sedgwick, Edward G.¹  Bragg, Philip D.¹ 

[1] Department of Biochemistry, University of British Columbia, 2146 Health Sciences Mall, Vancouver V6T 1W5, Canada

关键词: N-Phenyl-1-naphthylamine;    Lipophilic probe;    Cytochrome o;    Proteoliposome;    Oxidation-reduction state;   

DOI  :  10.1016/0014-5793(88)80811-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

N-Phenyl-1-naphthylamine (NPN), a reagent which has been used previously to probe the fluidity or microviscosity of the membrane lipids of intact cells of Escherichia coli, was found to respond to the redox state of purified cytochrome o incorporated into lipid vesicles formed from purified or E. coli phospholipids. NPN was bound to the proteoliposomes to produce a steady-state level of fluorescence intensity. Addition of the substrate ascorbate, in the presence of phenazine methosulfate as an electron donor, did not alter the fluorescence. However, following complete removal of oxygen from the medium by oxidation of the substrate by molecular oxygen catalyzed by cytochrome o, there was an increase in the fluorescence of NPN. This coincided with the reduction of cytochrome o. Reoxidation of the cytochrome by addition of oxygen decreased the fluorescence to steady-state levels until the oxidant had been completely reduced. The fluorescence changes were dependent on the incorporation of cytochrome o into phospholipid vesicles but were insensitive to the state of energization of the vesicle membrane.

【 授权许可】

Unknown