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U Yamaguchi-Koll

Publications and source records attributed to U Yamaguchi-Koll.

4 recordsLinked to original sources
PubMed1977

Differences in the physical properties of dense and standard poliovirus particles.

Dense poliovirus particles (DP) differ in buoyant density, sedimentation coefficient and lability from standard poliovirus particles. Dense particles band at a density of 1-44 g/ml in isopycnic CsCl gradients and sediment in sucrose gradients at 220S. However, when DP are centrifuged in sucrose gradients containing 1-5 M-KCl, NaCl or LiCl, two types of particles are observed, one sedimenting at 220S and the other at 160S. Particles sedimenting at 220S are converted into particles sedimenting at 160S by incubation at 37 degrees C in 1-5 M-KCl. The high buoyant density seems to be correlated with the high lability of DP. Dense particles are extremely labile in isotonic phosphate-buffered saline. Their degradation proceeds through an RNA-containing particle lacking polypeptide VP4, to RNA and empty capsids.

Capsid↗
PubMed1975

Isolation and characterization of 'dense particles' from poliovirus-infected HeLa cells.

Dense poliovirus particles (buoyant density 1.44 g/ml in CsCl) isolated from infected HeLa cells contain the normal four structural polypeptides VP1 to VP4, and 35S 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.

Amino Acids↗
PubMedDate not supplied

Dissociation and reassociation of poliovirus. II. Protein components obtained by urea treatment of the virus particle.

Dissociation of poliovirus by 9 M urea in 0.015 M NaCl at 25 degrees C resulted in the liberation of 35S RNA and of polypeptides sedimenting at 2S in sucrose gradients containing 9 M urea. However, a ribonucleopolypeptide (RNPP) complex sedimenting at 45S and oligomers of the viral polypeptides sedimenting at 7--8S were found in addition to the monomers sedimenting at 2S when the urea concentration was lowered to 5 M after the dissociation procedure. Ribonuclease treatment prevents the appearance of the RNPP-complex. The amount of the RNPP-complex decreased, when the dissociation was performed at higher ionic strength. Under these conditions small amounts of empty capsids were detected. Polyacrylamide gel electrophoresis showed that the RNPP-complex contained the polypeptide VP1. The oligomers (7--8S) contained the polypeptide VP3 and small amounts of VP2. The bulk of VP2 and some VP3 were found in the 2S position together with VP4. The molecular weight of the dissociation products in urea and phosphate buffer was determined by gel filtration to be about 30,000 for the monomeric polypeptides containing predominantly VP2 and about 70,000 for the oligomeric polypeptides containing predominantly VP3. Our results demonstrate that the oligomers and the RNPP-complex are not primary products obtained by dissociation of the virus particle by urea but are due to a reassociation of the polypeptides or of VP1 and RNA.

Centrifugation, Density Gradient↗