Figure 3. Binding of aptamer to mutants of gp120.

Truncation mutants (b) and point mutants (c) of gp120 were tested for binding to aptamer 299.5 (a) in an aptamer-gp120 binding assay. In (b) the gp120 was pre-incubated in the presence or absence of CD4 prior to aptamer binding. EC50 values generated from binding curves are expressed relative to binding to wild type gp120. Mutants whose binding is significantly different from that of the wild-type as determined by a T-test are indicated by asterisks, where *, ** and *** indicate p values of less than 0.05, 0.01 and 0.001 respectively.