Figure 1.
Negative-stain micrographs of P1247 procapsids in (A) low-salt and (B) high-salt at different temperatures within 20–70°C as indicated. Significantly more expanded (white arrowheads) than compact (white arrows) particles were observed in the high-salt conditions. (C) Negative-stain micrographs of P1’247 procapsids in 0.3M KCl and at 20° and 40°. All particles were already expanded at 40°C and no intact particles were detected at 60°C or higher temperatures. Scale bars: 300 Å. (D) Differential scanning calorimetry of P1247 procapsids in low salt (blue curve) and 0.3 M KCl (red curve) buffers. The endothermic peaks were fitted with a non-two state model (black curves).