HIV-1 Protease flap region sensitivity to solution viscosity and osmotic pressure

PHYS 376

Luis Galiano, lgaliano@chem.ufl.edu and Gail E. Fanucci, fanucci@chem.ufl.edu. Department of Chemistry, University of Florida, PO Box 117200, Gainesville, FL 32611
In the present work, the effects of osmotic pressure and solution viscosity on the conformations of the flap region of HIV-1 Protease (HIVPR) are explored with Site-directed spin labeling EPR spectroscopy. The K55C spin labeled mutant of HIV-1 protease was used for these studies. By combining analysis of EPR line shapes with distance distribution profiles from pulsed DEER measurements, we have systematically evaluated the effects that solution viscosity and osmolality have upon protein correlation time, internal modes of spin label motion and large amplitude conformational changes in the flaps. Experiments performed in the presence and absence of inhibitor reveal that osmotic pressure and solution viscosity are more likely altering local probe dynamics with little to no effect on the conformations of the flaps.
 

PHYS Poster Session - General Experiment
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008