Figure 4
C10-IMD binds to a single site in Rv3160c and the interaction does not cause changes in the secondary structure of the protein. (A) Fluorescence quenching spectra of Rv3160c. The 10 µM Rv3160c in PBS solution is excited and quenching of fluorescence is recorded in the presence of varying concentrations of C10-IMD (1–100 μM). (B) Stern–Volmer plot of decrease in mean fluorescence intensity of Rv3160c in the presence of varying concentrations of C10-IMD derived from three independent experiments. The dynamic quenching rate constant Ksv is evaluated from the slope of the line. (C) Logarithmic plot of mean relative fluorescence quenching of Rv3160c derived from three independent experiments against logarithmic concentrations of C10-IMD. KD is calculated from the intersection of the line with the y axis and the number of binding sites (n) from the slope of the line. (D) CD spectra of Rv3160c in the presence of 1 µM or 10 µM 86 bp rv3161c upstream fragment (DNA) (Fig. 2C). (E) CD spectra of Rv3160c in the presence of 10 µM or 100 µM C10-IMD. Error bars in (B) and (C) indicate standard deviation.
