Fig. 3
From: LsrB-based and temperature-dependent identification of bacterial AI-2 receptor
Thermal stability of AI-2. The different concentrations of AI-2 solution 40.0 μM (a), 10.0 μM (b) and 2.5 μM (c), respectively. Then, the AI-2 solution was incubated for 10 min at 37, 45, 50, 55, 60, 65 or 70 °C, respectively. After a 10-min incubation, the AI-2 solution was filtered through a 0.22-μm filter (EMD Millipore) to obtain cell-free CF for detection of AI-2 activity. AI-2 activity was expressed as relative light units (RLUs). The results of the thermal stability assay showed that AI-2 activity was relatively high at incubation temperatures of less than 65 °C. Furthermore, an incubation temperature of 45–65 °C had no significant effect on AI-2 activity. Experiments were repeated three times