Interaction
of fluorescent molecules BODIPY FL vinblastine (4), BODIPY
FL catharanthine (19), BODIPY FL vindoline
(20), or sulfo-Cy5 vindoline (21) with 5
nM GST-hPXR-LBD and 5 nM Tb-anti-GST after 30 min of incubation. (A)
Binding of indicated concentrations of BODIPY FL vinblastine (4) to either 5 nM Tb-anti-GST; 5 nM GST-hPXR-LBD in the presence
of either DMSO (total binding) or TO901317 (1, 10 μM,
background binding); or to 5 nM Tb-anti-GST, 5 nM GST, and DMSO (absolute
background binding). (B) Binding of indicated concentrations of BODIPY
FL catharanthine (19) to either 5 nM Tb-anti-GST; 5 nM
GST-hPXR-LBD in the presence of either DMSO (total binding) or TO901317
(1, 10 μM, background binding); or to 5 nM Tb-anti-GST,
5 nM GST, and DMSO (absolute background binding). (C) Binding of indicated
concentrations of BODIPY FL vindoline (20) to either
5 nM Tb-anti-GST; 5 nM GST-hPXR-LBD in the presence of either DMSO
(total binding) or TO901317 (1, 10 μM, background
binding); or to 5 nM Tb-anti-GST, 5 nM GST, and DMSO (absolute background
binding). (D) Binding curves of indicated concentrations of sulfo-Cy5
vindoline (21) to either 5 nM Tb-anti-GST; 5 nM GST-hPXR-LBD
in the presence of either DMSO (total binding) or TO901317 (1, 10 μM, background binding or nonspecific binding);
or to 5 nM Tb-anti-GST, 5 nM GST, and DMSO (absolute background binding).