Summary of amino acid residues in hENT1 important for sensitivity to inhibitors or affinity for various substrates
The fold decrease in sensitivity to inhibition (Ki or IC50) or affinity (Km) relative to the wild-type transporter is shown.
| Amino Acid Residue in hENT1 | Inhibitors | Substrates | Reference | ||||||
|---|---|---|---|---|---|---|---|---|---|
| NBMPR | Dipyridamole | Dilazep | Soluflazine | Adenosine | Inosine | Guanosine | Cytidine | ||
| Met33 | 0.62 | 11 | 10 | 4.5 | N.D. | N.D. | N.D. | N.D. | Visser et al., 2002a |
| Met89Cys | 3.7 | N.S.D. | N.S.D. | N.D. | 7.9 | N.D. | 5.7 | N.D. | Tables 2, 3, 4 |
| Leu92Gln | 222 | N.S.D. | 3.8 | N.D. | N.S.D. | 4 | N.D. | N.D. | Endres et al., 2004 |
| Gly154Ser | 2500 | 3 | 7 | N.D. | 3 | N.D. | N.D. | 3 | SenGupta and Unadkat, 2004 |
| Ser160Cys | 5.8 | 2.6 | N.S.D. | N.D. | 2.7 | N.D. | 1.8 | N.D. | Tables 2, 3, 4 |
| Gly179 | 6 | N.D. | N.D. | N.D. | N.D. | N.D. | N.D. | N.D. | SenGupta et al., 2002 |
| Asn338 | 2.4 | 10 | 3.4 | 14 | N.D. | N.D. | N.D. | N.D. | Visser et al., 2002b |
| Met33/Asn338 | 1.4 | 13 | 67 | 7.2 | N.D. | N.D. | N.D. | N.D. | Visser et al., 2002b |
| Met89/Ser160 | 19 | 4.7 | N.S.D. | N.D. | 7.8 | N.D. | 7.7 | N.D. | Tables 2, 3, 4 |
N.S.D., not significantly different; N.D., not determined.