TABLE 1.
Amino acid homology between the SF162, SF2, and US4 gp120 envelopes and the peptides used during the antibody-peptide competition studies
| Peptide | Regiona | % Homology withb:
|
||
|---|---|---|---|---|
| SF162 | SF2 | US4 | ||
| LHCTNLENATNTTSS | (V1 Nt) | 87 | 67 | 53 |
| TSSNWKEMNRGEIKN | (V1 Ct)c | 93 | 80 | 60 |
| TTSIRNKMQKEYALF | (V2 Nt) | 100 | 80 | 73 |
| YKLDVVPIDNDNTSY | (V2 Ct)d | 100 | 66 | 93 |
| CSFKVGAGKLINC | (V2 base)e | 77 | 60 | 70 |
| CKSITIGPGRAFYATGDC | V3 loop | 100 | 75 | 94 |
| NSTQLFNSTWNNTIG | V4 loopf | 100 | 60 | 66 |
| IRCSSNITGLLLTRD | V5 loop | 100 | 93 | 93 |
| EKLWVTVYYGVPVWKEATTT | (C1) | 100 | 100 | 90 |
| VPVWKEATTTLFCASDAKAY | (C1) | 100 | 95 | 100 |
| RPGGGDMRDNWRSELYKYKV | (C5) | 100 | 100 | 90 |
| VTIEPLGVAPTKAKRRVVQR | (C5) | 95 | 85 | 85 |
| CNTSVITQACPKISFEPIPI | (C2 Nt) | 95 | 90 | 95 |
| HYCAPAGFAILKCNDKKFSG | (C2 Nt) | 95 | 80 | 90 |
| KGSCKNVSTVQCTHGIRPVV | (C2 Ct) | 85 | 85 | 90 |
| STQLLLNGSLAEEEVVIRSE | (C2 Ct) | 95 | 95 | 90 |
Ct, carboxy terminal; Nt, amino terminal.
The values shown are percentages of homology in the amino acid sequence between the peptide used during our antibody-peptide competition studies and that of the corresponding region on the SF162, SF2, and US4 gp120 proteins. Amino acid insertions or deletions that exist in the SF162, SF2, and US4 amino acid sequence were not taken into consideration when determining the percent amino acid homology.
The carboxy-terminal side of the US4 V1 loop has an insert of 19 amino acids between the second serine and the first asparagine. The 60% homology corresponds to the remaining (shown) 15 amino acids.
The carboxy-terminal side of the SF2 V2 loop has a 5- amino-acid insert between the first aparagine and the second aspartic acid shown. The 66% homology corresponds to the remaining (shown) 15 amino acids.
The first five and last five amino acids forming the V2 loop of SF162 are common between the SF162 and ΔV2 envelopes. The 30 central amino acids of the SF162 V2 loop were replaced with the GAG tripeptide to generate the ΔV2 envelope.
A 2-amino-acid insertion between the third threonine and the isoleucine shown exists in the case of the US4 V4 loop. A single-amino-acid insertion following the tryptophan exists in the case of the SF2 V4 loop.