Table 1.
Estimated kinetic constants for binding of full-length HIV-1 Vpr and C-terminal Vpr peptides to CypA.
| Peptide | Amino acid sequence | Model | Kinetic constants | ||
|---|---|---|---|---|---|
| KD(μM) | ka1(1/Ms) | kd(1/s) | |||
| Vpr75-90 | GCRHSRIGVTRQRRAR | 1:1 | 0.28 ± 0.27 | 8.1 ± 6.1 × 104 | 6.3 ± 4.6 × 10-3 |
| Vpr75-90 (R76Q, V83I, T84I) | GCQHSRIGIIRQRRAR | 1:1 | 4.7 ± 2.6 | 1.6 ± 0.1 × 104 | 0.071 ± 0.037 |
| Vpr75-90 (R76Q, V83I, R80A, T84I) | GCQHSAIGIIRQRRAR | 1:1 | 2.7 ± 1.9 | 4.2 ± 0.8 × 104 | 0.095 ± 0.061 |
| Vpr75-90 (R80A) | GCRHSAIGVTRQRRAR | 1:1 | 7.5 ± 2.6 | 3.8 ± 0.6 × 103 | 0.027 ± 0.005 |
| Vpr69-78 | FIHFRIGCRH | * | |||
| Vpr75-84 | GCRHSRIGVT | * | |||
| Vpr81-90 | IGVTRQRRAR | * | |||
| Vpr87-96 | RRARNGASRS | * | |||
| Vpr1-96 (918 RU CypA) | BA | ka1 = 1.3 ± 1.0 × 104 ka2 = 5.9 ± 1.7 × 10-6 |
kd1 = 1.8 ± 0.2 × 10-3 kd2 = 6.7 ± 3.8 × 10-4 |
||
| Vpr1-96 (918 RU CypA) | 1:1 | 0.31 ± 0.28 | 3.2 ± 1.2 × 104 | 0.007 ± 0.005 | |
| Vpr1-96 (180 RU CypA) | BA | ka1 = 5.8 ± 0.8 × 103 ka2 = 1.6 ± 1.6 × 10-4 |
kd1 = 0.022 ± 0.025 kd2 = 7.3 ± 4.0 × 10-4 |
||
| Vpr1-96 (180 RU CypA) | 1:1 | 0.32 ± 0.14 | 1.6 ± 0.6 × 104 | 4.22 ± 0.4 × 10-3 | |
The data represent mean values ± S.E. of two individual experiments using four different concentrations containing duplicate of one concentration.
*KD not measurable by the Biacore instrument.
1:1, Langmuir binding
BA, Bivalent analyte