Table 2.
Effect of single point mutations on the neutralization of the ConC virus by the UCLA1 aptamer
| gp120 region | Binding site | ConC gp120 mutation(s)a | Mutant IC50 (nM)b,c | Fold effect for mutant vs wild typec,d |
|---|---|---|---|---|
| C1 | CoR | K121A | 28 | 17 |
| CD4 | L125A | 40 | 24 | |
| V3 | K305A | 41 | 25 | |
| I307A | 36 | 22 | ||
| R308A | 35 | 21 | ||
| CoR | H330Y | 17 | 10 | |
| N332A | 0.11 | 0.06 | ||
| C3 | CD4 | S365I | 6 | 4 |
| CD4 | L369P | 50 | 30 | |
| S375M | 4 | 2 | ||
| C4 | CoR | R419A | 34 | 20 |
| CoR | K421A | 1 | 0.6 | |
| CoR | I423A | 0.43 | 0.3 | |
| CD4 | V430A | 1 | 0.6 | |
| CoR | A440E | 3 | 1.8 | |
| C5 | F468V | 9 | 5.4 | |
| CD4 | G471E | 2 | 1.2 | |
| CD4 | D474A | 0.46 | 0.3 | |
| CD4 | R476A | 1 | 0.6 |
a
Amino acids were labeled based on HxB2 numbering. The residues are defined according to the designations by Kwong, Zhou, and colleagues (28, 57).
b
The mutant IC50 is the concentration of the UCLA1 aptamer that inhibited 50% of infection of the respective mutant.
c
Values representing a significant neutralization resistance are shown in bold. Values represent the average of at least three independent experiments.
d
The fold decrease in neutralization sensitivity to the aptamer was calculated as mutant IC50/wild-type IC50. The wild-type IC50 was calculated as an average of 1.67 nM.