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 .
C0030012
redox state
C0010798
cytochrome