Effects of the porphyrin oxidation state on the conformations of c-type cytochromes

CHED 979

Tim L. Vuong, tvuong@csu.edu1, Kristy L. Mardis, kmardis@csu.edu1, and David M. Tiede, tiede@anl.gov2. (1) Department of Chemistry and Physics, Chicago State University, 9501 S King Drive, Chicago, IL 60628, (2) Chemistry Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439
The increase in petroleum prices has sparked renewed interest in alternative fuel sources such as solar energy. C-type cytochromes are being studied as possible building blocks for solar energy devices. Experimental wide-angle X-ray scattering studies have found that the c-type cytochrome (PDB entry 1os6) have identifiably different conformations in the reduced and oxidized form. The current work seeks to determine if the charmm force field can reproduce the experimental scattering pattern. The starting crystal structures were subjected to nano-second scale molecular dynamics simulations in a water sphere. The scattering profiles calculated from the ensemble of structures for both the oxidized and reduced structures were then compared to experiment. The results will indicate the ability of the charmm forcefield to distinguish between two proteins differing only in the charge state of the irons in the three heme groups.
 

Undergraduate Research Poster Session: Physical Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

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