FIG. 5.
Analysis of the ability of bacterium-bound CD59E to prevent cell death by using the bioluminescent recombinant E. coli strain EH234. A gene (lucGR) encoding the luciferase enzyme was cloned and expressed in E. coli EH234 (Ra). The recombinant bacteria were incubated with CD59E or VBS as for Fig. 2 and treated with increasing concentrations of NHS. d-Luciferin, the substrate for luciferase, was added, and the luminescence of the bacteria was measured after 60 min with a luminometer. In the presence of the luciferase enzyme and luciferine substrate, the bacteria emit green light but cell death leads to the loss of enzyme activity and light emission. Mean (±SD) values of quadruplicates are shown in this representative example of four similar experiments.