FIG. 4.

Detection of gp41-specific antibodies using synthetic peptides comprising cluster I sequences (aa 580 to 623). The percent reactivities of HIV-1 group M plasma specimens are shown for consensus group M peptide (■) and group O peptide (▨) or homologous regions of group N peptide (░⃞) and SIVcpz peptide (▩). The 44-mer peptides representing consensus sequences include group M (WGIKQLQARVLAVERYLKDQQLLGIWGCSGKLICTTAVPWNASW), group O (WGIRQLRARLLALETLIQNQQLLNLWGCKGKLVCYTSVKWNRTW), group N (WGIKQLQAKVLAIERYLRDQQILGSLGCSGKTICYTTVPWNETW), and SIVcpz (WGVKQLQARLLAVERYLQDQQILGLWGCSGKAVCYTTVPWNNSW). All 131 samples, regardless of substitution in gp41 regions, reacted with the gp41 group M peptide-based EIA, and a high degree of cross-reactivity to HIV-1 group O and N peptides and in SIVcpz peptide was observed.