Isolation and Characterization of 'Dense Particles' from Poliovirus-infected HeLa Cells

Abstract

SUMMARYDense poliovirus particles (buoyant density I"44 g/ml in CsC1) isolated from infected HeLa cells contain the normal four structural polypeptides VPI to VP4, and 35 S poliovirus RNA. In addition, small amounts of VPo and single-stranded RNA sedimenting slower than the poliovirus genome are present. Dense particles have a low specific infectivity, are neutralized by type-specific poliovirus antisera, and are detected during growth as early as normal virus but disappear when virus production stops. They appear to represent a different, more open, conformation of the normal virus capsid.

Echovirus 11 Dense Particles: Isolation and Preliminary Characterization

“…particles of higher buoyant density (density 1-44 g/ml) in CsC1 than standard particles (density 1.33 g/ml), have been described for several picornaviruses: poliovirus, coxsackie B5 virus, mengovirus, bovine enterovirus, and swine vesicular disease virus (SVDV) (Rowlands et at., 1975;Yamaguchi-Koll et al, 1975;Wiegers et al, 1977;Perez-Bercoff et al, 1978). Antigenic properties and chemical properties, such as amount of RNA, polypeptide composition, and RNA to protein ratio, are similar for dense and standard particles.…”

Monospecific Antisera Against Capsid Polypeptides of Poliovirus Type 1 Distinguish Antigenic Structures of Poliovirus Proteins

“…The growth of HeLa S 3 cells, the purification of poliovirus, type 1, strain Mahoney, the preparation of labelled poliovirus and virus-specific proteins in infected cells has been described previously (Yamaguchi-Koll et al, 1975;Wiegers & Dernick, 1981). Briefly, suspension cultures of HeLa $3 cells were infected at high multiplicity (100 p.f.u./cell); 20 to 50 ~tCi/ml [35S]methionine (> 600 Ci/mmol) was added at 3.5 h after infection.…”

“…For the preparation of cytoplasmic extracts, samples of infected cells were collected and immediately frozen at -80 °C. Labelled virus was prepared from cells, collected 6 h after infection and purified as described previously (Yamaguchi-Koll et al, 1975).…”

Poliovirus-specific Polypeptides in Infected HeLa Cells Analysed by Isoelectric Focusing and 2D-Analysis

“…The growth of HeLa S a cells and the purification of poliovirus type 1, strain Mahoney, have been described previously (Yamaguchi-Koll et al, 1975).…”

“…However, in all polioviruses tested, VP1 was the most basic and VP3 the most acidic polypeptide, and the order of decreasing pI was always VP1, 4, 2, 3 (Hamann et aL, 1978;Drzeniek et al, 1980). Due to the great differences in pI values, a preparative procedure of isoelectric focusing in urea-sucrose gradients yielded excellent separations of all four capsid polypeptides (Wiegers & Drzeniek, 1980). The problems created by isoelectric focusing in high concentrations of urea were overcome in a methodological study in which rules were elaborated for the analysis of capsid proteins by isoelectric focusing and 2D-analysis (Hamann & Drzeniek, 1978).…”