TABLE 2.
Summary of ITC experiments of ligand-bound hRARα association with SRC-1
| Ligand | Kd (μM)a |
| ATRA | 0.65 ± 0.01 |
| apo-receptor | 5.97 ± 0.94 |
| apo-13-lycopenone | 39.67 ± 10.0 |
| BMS-195614 | 115.7 ± 61.6 |
a
The Kd of SRC-1 peptide binding to purified apo hRARα-LBD or liganded receptor; average data ± 1 SD from n = 3. Ligand-bound receptors were compared with apo-receptor using pair-wise t-tests for the Kds of the SRC-1 coactivator peptide. ATRA-bound receptor showed a significantly decreased (P < 0.001) Kd indicating increased affinity of coactivator binding (i.e., agonist behavior). Significant increases in SRC-1 Kd were observed for receptors with bound apo-13-lycopenone (P < 0.005) or the known antagonist BMS-195614 (P < 0.05).