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 | — |
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).