Electrostatic effects on funneled landscapes and structural diversity in denatured protein ensembles.
The denatured state of proteins is heterogeneous and susceptible to general hydrophobic and electrostatic forces, but to what extent does the funneled nature of protein energy landscapes play a role in the unfolded ensemble? We simulate the denatured ensemble of cytochrome c using a series of models. The models pinpoint the efficacy of incorporating energetic funnels toward the native state in contrast with models having no native structure-seeking tendency. These models also contain varying strengths of electrostatic effects and hydrophobic collapse. The simulations based on these models are compared with experimental distributions for the distances between a fluorescent donor and the heme acceptor that were extracted from time-resolved fluorescence energy transfer experiments on cytochrome c. Comparing simulations to detailed experimental data on several labeling sites allows us to quantify the dominant forces in denatured protein ensembles.
Weinkam
Patrick
P
Center for Theoretical Biological Physics and Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Pletneva
Ekaterina V
EV
Gray
Harry B
HB
Winkler
Jay R
JR
Wolynes
Peter G
PG
D003198:Computer Simulation; D045304:Cytochromes c / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D011487:Protein Conformation; D011489:Protein Denaturation; D011506:Proteins / Q000737:chemistry; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry; D055672:Static Electricity
D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D045304:Cytochromes c