TABLE 2.
Competitive inhibition of the HBx:DDB1 interactiona
| Competitorb | Mean IC50 (nM) (SEM) |
|
|---|---|---|
| His-HBx and GST-DDB1 expressed separatelyc | His-HBx:GST-DDB1 coexpressed | |
| HBx | 61 (±5) | 9 (±5) |
| SV5-V | 7 (±2) | 4 (±2) |
| DDB1 | 204 (±25) | 16 (±0.2) |
| HBx H-box peptide (wild type) | 5,000 (±1,000) | 1,560 (±93) |
| HBx H-box peptide (R96E mutant) | 166,000 (±37,000) | >100,000 |
| BSA | >3,000 | >100,000 |
a
The interaction between His-HBx and GST-DDB1 was measured by TR-FRET. Data are expressed as means (SEM) (n = 2 to 5 independent experiments). Note that the wild-type SV5-V H-box peptide also competitively inhibited HBx:DDB1 binding (data not shown).
b
Competitor proteins and peptides were not tagged. BSA, bovine serum albumin.
c
HBx expressed alone required detergent for solubilization.