Comparison of hOAT1 and rROAT1 substrate affinity
| Substrate | hOAT1 | rROAT1 |
|---|---|---|
| Km μM | ||
| Cidofovir | 46 | 238 |
| Adefovir | 30 | 270 |
| PAH | 4 | 70 |
Each Km was determined from a double reciprocal plot of a 20-min uptake at substrate concentrations ranging from 10 to 400 μM for hOAT1 (PAH was 2 to 20 μM because of its lower Km ) and 50 to 1000 μM for rROAT1. Plotted data were mean ± S.E. values from three to four animals (10 oocytes/concentration/animal), and Km values were rounded to the nearest whole number. Km data of PAH for rROAT1 are reproduced from Sweet et al., 1997.