TABLE 1.

Effect of Y₈₀₂W₈₀₃ substitution on the fusogenic capacity of HIV-1 Env glycoprotein

Mutant	No. of syncytia/well (293T/HeLa P4 cocultivation)a	% of wtb	Pc
NTd	0	NDe	ND
pcEnv-wt	719 ± 49	100	ND
pcEnv-Y802W803-SL	546 ± 88	76	<0.02
pcEnv-Y712-A	1,149 ± 74	159	<0.001

^aValues shown are the numbers of syncytia obtained per well and are the averages of three independent experiments performed in triplicate.

^bData are numbers of syncytia divided by the number obtained with wt pEnv-wt (719 ± 49 syncytia/well).

^cThe results for the mutant Env glycoproteins were compared to those for the wt by means of the t test for unpaired samples.

^dNT, cells transfected with the pcDNA3 vector alone.

^eND, not determined.