Kinetics of thermal denaturation of human rhinoviruses in the presence of anti-viral capsid binders analyzed by capillary electrophoresis.
In vivo, the icosahedral capsid of human rhinoviruses undergoes well-defined transitions during the infection pathway. Native virus, sedimenting at 150S, is converted to subviral particles with a sedimentation coefficient of 135S, which have lost the innermost capsid protein VP4. Upon release of the genomic RNA empty 80S capsids remain. Similar structural modifications are observed in vitro upon exposure to low pH and/or elevated temperature. Virions are stabilized against these transitions by various antiviral compounds, which bind to a hydrophobic pocket in the capsid protein VP1. Using capillary electrophoresis the kinetics of viral decay in the presence of such hydrophobic drugs was investigated. Assuming first-order kinetics, the increase of the time constant reflects the extent of stabilization. Exposure of the virions to 55 degrees C after presaturation with the antivirals increased the time constants (as compared to native virus) by a factor of 8-30, from a few minutes to several ten minutes. Denaturation of the stabilized capsid gave rise to heterogeneous material rather than to defined subviral particles. This was confirmed by electron microscopy and indicates that the structural modification of the virus follows a kinetically well-defined pathway which is disturbed by the drugs resulting in disorganized disruption of the virion.
Okun
Vadim M
VM
Institute for Analytical Chemistry, Medical Faculty, University of Vienna, Vienna, Austria.
Nizet
Stephane
S
Blaas
Dieter
D
Kenndler
Ernst
E
D000998:Antiviral Agents / Q000494:pharmacology*; D001565:Benzoates / Q000494:pharmacology*; D002213:Capsid / Q000187:drug effects* / Q000302:isolation & purification; D019075:Electrophoresis, Capillary / Q000379:methods; D006367:HeLa Cells; D006361:Heating; D006801:Humans; D007526:Isoelectric Point; D007555:Isoxazoles / Q000494:pharmacology*; D007700:Kinetics; D011758:Pyrroles / Q000494:pharmacology*; D012229:Rhinovirus / Q000187:drug effects* / Q000302:isolation & purification; D013696:Temperature; D013997:Time Factors
D000998:Antiviral Agents; D001565:Benzoates; C461879:EB 2345; D007555:Isoxazoles; D011758:Pyrroles; C059730:Win 52035; C049869:Win 52084