TABLE 1.
KI of AgG3z8 mutant proteins obtained by competition binding assays
The concentration of wild-type 125I-AgG3z8 was kept constant at 10 nm. Ligand binding activity in the absence of competitors was normalized to 100%, and the amount of bound ligands was calculated from the reduction in 125I-AgG3z8. KI values were calculated from the IC50 concentration of competing ligands by the equation of Cheng and Prusoff (46). For comparison, the KD values estimated by Scatchard plot were 9.3 nm, 367 nm, 1.1 μm, and 1.2 μm for AgG3z8, AgG3z8D1820/1899A, AgG3z8N4A, and AgG3z0, respectively (Fig. 9B).
| Ligand | KII |
|---|---|
| nm | |
| E1A | 4.6 |
| L2A | 6.2 |
| T3A | 39 |
| N4A | 2,100 |
| E5A | 85 |
| I6A | 110 |
| P7A | 74 |
| AgG3z0 | 1,800 |