TABLE 1

Kinetic parameters associated with substrate transport by OAT1, OAT2, OAT3, and OCT2

The actual kinetic experiments associated with OAT2-mediated antiviral transport are shown in Fig. 6. The concentration of unlabeled substrate ranged from 0 to 1000 μM. The kinetic parameters associated with OAT1- and OAT3-mediated acyclovir transport and probe substrate transport by OAT1 (PAH), OAT3 (ES), and OCT2 (MPP) are shown for comparison. Transport efficiency was determined by dividing the Jmax value by the Km value. Kinetics of OAT2-mediated acyclovir, ganciclovir, and penciclovir transport were conducted on the same day using cells of the same passage. n = 3 to 4 different passages; data are means ± S.E.M.

TransporterSubstrateJmaxKmTransport Efficiency
pmol · min1 · mg protein1μMμl · min1 · mg protein1
OAT2Acyclovir561 ± 6594 ± 86
OAT2Ganciclovir1838 ± 374264 ± 247
OAT2Penciclovir6675 ± 576284 ± 1023
OAT1PAH230 ± 3420 ± 311
OAT3ES436 ± 26217 ± 1026
OCT2MPP141 ± 192.7 ± 0.252