It’s alive!: The phenomenon of viral breathing
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Transcript of It’s alive!: The phenomenon of viral breathing
IT’S ALIVE!: THE PHENOMENON OF VIRAL BREATHING
STRUCTURAL JOURNAL CLUB
AUGUST 25, 2011
WHAT IS VIRAL BREATHING?
Breathing is when the capsid undergoes reversible conformational changes not induced by an outside source.
Example: An eternal epitope is exposed on the capsid surface periodically without the presence of receptor.
DIGESTION TIME COURSE
CRYSTAL STRUCTURE OF VP4
DIGESTION IN THE PRESENCE OF DRUG
DIGESTION WITH ANTIBODY
STABILITY OF DIGESTION
Mutant: V1188M/C1199W
INTERNAL NEUTRALIZATION SITES
VP4 VP1 N terminus
TEMPERATURE DEPENDENCE
REVERSIBILITY OF INTERNAL NEUTRALIZATION
NEUTRALIZATION BY VP4 ANTIBODY
CROSS REACTIVITY OF ANTIBODIES
CVB3 STRAIN CPE
Three strains of CVB3:
- 28 – cause complete CPE on HeLa but not RD, representative strain
- RD – DAF binding strain
- RDVa – variant of RD which emerged from carrier culture
HEMAGGLUTINATION (DAF BINDING)
LIGAND BINDING OF CVB3
CVB3/28 CVB3/RD CVB3/RDVa
HeL
a
RD
Car
rier
RD
CAR
DAF
GROWTH CURVES
HeLa RD Carrier RD
CVB3/28 CVB3/RDVa CVB3/RD
CVB3 DECAY
CVB3/28 CVB3/RD CVB3/RDVa
AMINO ACID CHANGES IN CVB3
WHAT WE HAVE DONEIncubated CVB3-RD with CAR at 4 °C, RT, and 37 °C and saw the following:
4°
37°37°
RT
WHAT WE WANT TO DO
• Repeat Carson’s decay experiment to determine what the virus is doing to loose infectivity
• Negstain of different time points• Gel of time points• Western of time points
• Eventually would like to put it on affinity grid
• Virus on lipid alone without receptor to determine whether it will undergo conformation change on lipid alone
• Receptor doesn’t bind all over the virus – only one position
NOW FOR SOMETHING COMPLETELY DIFFERENT!
WARNING: YOU SHOULD NOT TRY THE FOLLOWING AT HOME! YOU WILL NEVER BE ABLE TO PUBLISH THIS!
135S AND 135S-P1
80S-P1 COMPLEXES
P1 FAB ON PV
1 OR 8 PARTICLE RECONSTRUCTION