FIG 3.

Fluorescence (excitation, 490 nm; emission, 515 nm) obtained using different fluorogenic probes for reporter enzyme fluorescence (REF) with the TEM-1, AmpC, and BlaC β-lactamases. Fluorescence after 3 h coincubation of 1 μM CDG-1 (A), CDG-OMe (B), and CDG-3 (C) with between 0.1 and 500 nM each β-lactamase at room temperature in MES buffer, pH 6.0. Data points shown represent the average fluorescence from samples done in triplicate, and error bars represent the standard deviations for these data. P values are shown above data points and are derived from comparison of data for BlaC with that of TEM-1 by ANOVA. Structure for the probe used is shown to the right of their graph for activity with the β-lactamases.