FIG. 1.

(A) Particle-to-infectivity ratios of wild-type and gC mutant viruses. NS or NS-gC_null virus (10⁶ PFU of each) was tested by Western blotting for viral capsid antigen VP5. Bands were quantified by densitometry. The two viruses had similar PFU/VP5 ratios, which indicates comparable plaquing efficiency. Sizes are indicated in kilodaltons. (B) Attachment kinetics of NS or NS-gC_null virus. [³⁵S]methionine- and [³⁵S]cysteine-labeled cell-free virus was added to HEp-2 cells at 4°C, and at various times bound counts were determined. NS and NS-gC_null have similar binding kinetics.