TABLE 2.
[125I]NGF binding to HEK293 cells stably expressing TrkA mutant receptorsa
| Receptor | Bindingb | Mean Kd (nM) ± SEM |
|---|---|---|
| TrkA | +++ | 0.9 ± 0.1 |
| L92V L95V | +++ | 1.0 ± 0.1 |
| P287A | +++ | 1.2 ± 0.1 |
| C302S | NB | NB |
| P313A | +++ | 1.0 ± 0.2 |
| W317A | + | 2.5 ± 0.3 |
| W317F | ++ | 1.7 ± 0.2 |
| C348S | +++ | 0.7 ± 0.1 |
a
Cells were washed and resuspended in PBS with bovine serum albumin and glucose at a concentration of 2 × 106 cells/ml. Binding under equilibrium conditions was carried out with different [125I]NGF concentrations for 2 h at 1°C. The values were calculated from triplicate determinations. Nonspecific ligand binding, which was determined in the presence of a 100-fold excess of unlabeled NGF, was subtracted from the total amount of cell-bound NGF.
b
+++, 80 to 100% TrkA binding; ++, 40 to 80% TrkA binding; +, 20 to 40% TrkA binding; NB, no binding.