Vanadate-sensitive ATPase activity of DMRPs in Sf9 inside-out vesicles.

A: Time course of ATPase activity measured in the presence of 3.3 mM Mg2+ATP at 37 ˚C using 30 μg total Sf9 membrane protein overexpressing wild type DMRP in the absence or presence of 1 mM MTX. B: ATPase activity as a function of Mg2+ ATP concentration measured at 37 ˚C for 5 minutes using 30 and 100 μg Sf9 IOV preparations overexpressing wild-type or K687M/K1349M DMRP, respectively in the absence or presence of 1 mM MTX. C: ATPase activity as a function of MTX concentration measured at 37 ˚C for 5 minutes in the presence of 3.3 mM Mg2+ ATP using 30 and 100 μg Sf9 IOV preparations overexpressing wild type or K687M/K1349M DMRP, respectively. D: ATPase activity of the wild type DMRP in the absence or the presence of organic anion inhibitors, MK571 and benzbromarone (BB), measured at 37 ˚C at 3.3 mM Mg2+ ATP concentration using 30 μg Sf9 IOV preparations overexpressing wild type DMRP in the absence (white bars) or in the presence (black bars) of 1 mM MTX. Figures depict mean values of at least three independent experiments done in at least duplicates. Of note, the standard error of the estimate of mean value (S.E.M.) is depicted for all of the data points in Fig 1, however error bars are often not visible due to the low scattering of the data. We used unpaired two tailed t-test for statistical analysis of data in 1D. Significance is indicated as *p≤0.05, **p≤0.01, ***p≤0.001 and ****p≤0.0001 between control and MK571 or BB inhibited samples in the absence or in the presence of 1mM MTX.