TABLE 1

Kinetic parameters for the transport of E-sul and EG by HEK293 cells expressing each chimeric OATP1B1 protein

Data shown in Fig. 4 were used to determine these parameters calculated using nonlinear regression analysis as described under Materials and Methods. Each parameter represents the mean ± computer-calculated S.D.


Transporter

Km

Corrected Vmax

Corrected Vmax/Km
μM pmol/min/mg protein μl/min/mg protein
E-sul
    OATP1B1 0.162 ± 0.015 34.2 ± 1.4 211 ± 21
    1B1-TM1-3 0.112 ± 0.022 9.74 ± 0.75** 86.7 ± 17.9**
    1B1-TM1-6 0.723 ± 0.130** 29.8 ± 3.3 41.2 ± 8.8**
    1B1-TM1-7 1.34 ± 0.30** 17.8 ± 2.8** 13.3 ± 3.6**
    1B1-TM1-8 4.42 ± 0.74** 40.2 ± 5.4 9.08 ± 1.95**
    1B1-TM1-9 Not significantly transported
EG
    OATP1B1 5.76 ± 0.28 135 ± 5 23.5 ± 1.4
    1B1-TM1-3 2.69 ± 0.09** 70.7 ± 1.6** 26.3 ± 1.0
    1B1-TM1-6 7.17 ± 0.41** 60.7 ± 2.7** 8.47 ± 0.62**
    1B1-TM1-7 7.65 ± 0.86 31.9 ± 2.8** 4.17 ± 0.60**
    1B1-TM1-8 13.1 ± 2.1** 17.8 ± 2.4** 1.37 ± 0.29**
    1B1-TM1-9

Not significantly transported

  • ** P < 0.01, significantly different from native OATP1B1.