It’s alive!: The phenomenon of viral breathing

1. It’s alive!: The phenomenon of viral breathing Structural Journal Club August 25, 2011

2. 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.

4. Digestion Time Course

5. Crystal Structure of VP4

6. Digestion in the presence of Drug

8. Digestion with Antibody

9. Stability of Digestion Mutant: V1188M/ C1199W

11. Internal neutralization sites VP1 N terminus VP4

12. Temperature Dependence

13. Reversibility of Internal Neutralization

15. Neutralization by vp4 antibody

16. Cross reactivity of antibodies

18. 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

19. Hemagglutination (daf binding)

20. Ligand Binding of CVB3 HeLa RD Carrier RD DAF CAR CVB3/RD CVB3/RDVa CVB3/28

21. Growth Curves HeLa RD Carrier RD CVB3/28 CVB3/RD CVB3/RDVa

22. CVB3 Decay CVB3/RDVa CVB3/28 CVB3/RD

23. Amino Acid Changes in CVb3

24. What we have done • Incubated CVB3-RD with CAR at 4 °C, RT, and 37 °C and saw the following: RT 4° 37° 37°

26. 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

27. Now for something completely different! Warning: you should not try the following at home! You will never be able to publish this!

29. 135S and 135s-p1

30. 80s-p1 complexes

31. P1 fab on PV

32. 1 or 8 Particle reconstruction