Dynamic similarity of the unfolded states of proteins L and G.
The formation of specific intramolecular contacts has been studied under a range of denaturing conditions in single domains of the immunoglobulin-binding proteins L and G. Although they share no significant sequence similarity and have dissimilar folding pathways, the two domains have a similar native fold. Our measurements show that the rates of forming corresponding contacts in the unfolded states of both proteins are remarkably similar and even exhibit similar dependence on denaturant concentration. The unfolded proteins were modeled using Szabo, Schulten, and Schulten (SSS) theory as wormlike chains with excluded volume; when combined with our experimental data, the SSS analysis suggests that the unfolded state becomes uniformly more compact and less diffusive (i.e., rearranges more slowly) with decreasing denaturant concentrations.
Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
Vijay R
VR
Singh
Michaela
M
Kopka
Yujie
Y
Chen
William J
WJ
Wedemeyer
Lisa J
LJ
Lapidus
D000465:Algorithms; D001426:Bacterial Proteins / Q000737:chemistry*; D003198:Computer Simulation; D004268:DNA-Binding Proteins / Q000737:chemistry*; D041961:Deuterium Exchange Measurement; D031541:Fluorescence Resonance Energy Transfer; D019791:Guanidine / Q000737:chemistry; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D008962:Models, Theoretical; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D020673:Protein Renaturation; D011506:Proteins; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000302:isolation & purification; D013816:Thermodynamics; D014364:Tryptophan; D014508:Urea / Q000737:chemistry
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C034284:IgG Fc-binding protein, Streptococcus; C116593:L-protein, Peptococcus magnus; D011506:Proteins; D011993:Recombinant Fusion Proteins; D014364:Tryptophan; D014508:Urea; D019791:Guanidine