TABLE 1.
Binding of gp120JR-FL alanine mutants to the CCR5 Nt sulfopeptidea
| V3 residue | % gp120-CD4 binding to CCR5 Nt sulfopeptide |
|---|---|
| C 296 | — |
| T 297 | — |
| R 298* | 11.6 |
| P 299 | — |
| N 300 | — |
| N 301* | 11.9 |
| N 302 | 16 |
| T 303* | 11.08 |
| R 304* | 47 |
| K 305 | 49 |
| S 306* | 87.5 |
| I 307 | — |
| H 308 | — |
| I 309 | — |
| G 310* | 83.1 |
| P 311* | 118.7 |
| G 312* | 118.7 |
| R 313* | 98.2 |
| A 314 | — |
| F 315 | 95 |
| Y 316* | 62.6 |
| T 317 | — |
| T 318 | 97.4 |
| G 319 | — |
| E 320* | 96 |
| I 321 | 15 |
| I 322* | 25.2 |
| G 323 | 15 |
| D 324* | 11.2 |
| I 325* | 14.3 |
| R 326* | 18.9 |
| Q 327 | — |
| A 328 | — |
| H 329 | — |
| C 330 | — |
a
The biotinylated CCR5 Nt sulfopeptide comprising residues 2 to 18 was immobilized on streptavidin-coated plates and incubated with soluble gp120-CD4 complexes. The mutated amino acids and their locations in gp120JR-FL are in the left column. Mutant gp120JR-FL-CD4-IgG2 binding to the sulfopeptide is expressed as a percentage of wild-type gp120JR-FL-CD4-IgG2. The values shown are averages of three independent experiments, and standard deviations were no more than ±20%. —, residue not studied. Residues within the crown of the V3 loop are in boldface. Highly conserved (>80%) residues are in italics. Asterisk, residue previously characterized for binding to the sulfopeptide (9).