Figure 2: RELMα kills bacteria by disrupting their membranes.
(A) Purified recombinant mRELMα or hRETN was added to mid-logarithmic phase Streptococcus pyogenes for 2 hours and surviving bacteria were quantified by dilution plating. Colony forming units (CFUs) are expressed as a percentage of untreated bacteria.
(B) 2.5 μM of mRELMα or hRETN was added to mid-logarithmic phase bacteria for 2 hours and surviving bacteria were quantified by dilution plating. Means±SEM are plotted.
(C) Antibacterial efficacy of mRELMα and hRETN against wild-type S. aureus and an isogenic S. aureus mutant that lacks staphyloxanthin (ΔCRTM). Means±SEM are plotted. *P<0.05 **P<0.01 by paired Student’s t-test.
(D) Carboxyfluorescein (CF)-loaded liposomes were exposed to 5 μM mouse RELMα. Dye efflux was measured over time and is expressed as a percentage of maximal efflux in the presence of the detergent octylglucoside (OG).
(E) Percentage of dye release for varying doses of RELMα at the 500s time point.
(F) Propidium iodide uptake by S. pyogenes in the presence of increasing concentrations of mRELMα. Assays were performed in triplicate. All results are representative of at least two independent experiments.