FIG. 4.

Effect of 3(2H)-isoflavene on binding of PV2 Sabin, R2/01, and D6/01 variants. HeLa cell monolayers were infected with 200,000 cpm of [³⁵S]methionine-labeled purified viruses in the presence or absence of the drug (20 μM). After 1 h of incubation at 4°C, the cells were washed with PBS and lysed with 0.2% Nonidet P-40, and the cell-bound radioactivity was measured in a beta-scintillation counter. A polyclonal antibody against PV2 Sabin was used as the virus binding inhibitor. The experiment was repeated three times. Solid bars, without 3(2H)-isoflavene; shaded bars, with 3(2H)-isoflavene; open bars, with anti-PV2 antibody.