TABLE 2

Summary of interaction kinetics of ES with OATP1A2 and the common protein-altering variants, p. Ile13Thr and p. Thr668Ser Uptake of [3H]ES (20 nM) was measured in the presence of various concentrations of unlabeled ES in Na+ buffer at pH 7.4 over 60 min. Each value represents the mean ± S.E. from three independent experiments. Transport data were fitted using nonlinear regression analysis. Significant differences in the kinetics parameters of the variant proteins compared to OATP1A2 reference are shown in boldface. p values were determined by comparing Km and Vmax values for each variant with OATP1A2 using one-way ANOVA and Tukey's multicomparison test with p < 0.05 as the criterion of significance.




OATP1A2

Ile13Thr

Thr668Ser
Km (μM) 13.6 ± 3.2 13.1 ± 2.5 11.2 ± 2.6
Vmax (pmol/mg protein/2 min)
127 ± 20.3
258.3 ± 32.7 *
104.9 ± 14.4
  • * p < 0.05