FIG. 5.
(A) Particle analysis by equilibrium density centrifugation of mutant prM(ΔR88/C79Y). Concentrations of protein E in the individual fractions were measured by SDS-ELISA, and the buoyant density of the particles was determined by measuring the sucrose density in the peak fraction. (B) Immunoblot of prM(ΔR88/C79Y) and prM(ΔR88/Y76C) virus particles, using prM(ΔR88), WT, and WTIMM (see Materials and Methods) as controls. Samples containing equal amounts of protein E (250 ng) were applied in all cases. The membrane was stained with a polyclonal rabbit serum raised against protein prM. The positions of the proteins prM, M*, and M are indicated on the right. Samples prM(ΔR88/C79Y), prM(ΔR88/Y76C), and prM(ΔR88) did not show a detectable M band.