FIG. 1.

Protein composition of open cores and VP6-open cores. Samples of open cores (lanes 2 and 3), VP6-open cores (lane 4), and double-shelled particles (lane 5), each containing 5 μg of VP2, were analyzed by SDS–12% PAGE followed by staining with Coomassie blue. VP6 (4 μg) recovered from CaCl₂-treated double-shelled particles was resolved in lane 1. The cores that were resolved in lane 2 were incubated with [α-³²P]GTP prior to electrophoresis. VP3-GMP complexes that formed in this sample were identified by autoradiography (lane 6) and were used to confirm the position of VP3 in the gel.