TABLE 1.

Effects of amino acid substitutions at positions 29 to 43 of recombinant HIV-1 gp41 on ENF binding to the first heptad repeat and on the antiviral activity of ENF

Amino acid sequenceaBinding (B50 [μg/ml]) (fold change)bAntiviral activity (IC50 [μg/ml]) (fold change)b
QARQLLSGIVQQQNN 0.100.009
RARQLLSGIVQQQNN 0.24 (2.4)ND
QARLLLSGIVQQQNN 0.30 (3.0)0.005 (<1)
QARQLLSDIVQQQNN 0.70 (7.0)0.091 (10.1)
QARQLLSSIVQQQNN 0.95 (9.5)0.063 (7.0)
QARQLLSGIAQQQNN ND0.160 (17.8)
QARQLLSGIVHQQNN 0.25 (2.5)0.011 (1.2)
QARQLLSGIVQHQNN 4.33 (43.3)0.256 (28.4)
QARQLLSGIVQQQND 4.96 (49.6)0.210 (23.3)
  • a Positions 29 to 43 of gp41. Substituted amino acids are given in bold.

  • b Spearman nonparametric correlation analysis indicated a significant correlation between the measured binding affinities and antiviral activities (Spearman r = 0.82143; P = 0.0234). ND, not determined.