Biology – Quantitative Biology – Biomolecules
Scientific paper
2008-02-05
Biology
Quantitative Biology
Biomolecules
Scientific paper
10.1529/biophysj.108.131037
Despite the spontaneity of some in vitro protein folding reactions, native folding in vivo often requires the participation of barrel-shaped multimeric complexes known as chaperonins. Although it has long been known that chaperonin substrates fold upon sequestration inside the chaperonin barrel, the precise mechanism by which confinement within this space facilitates folding remains unknown. In this study, we examine the possibility that the chaperonin mediates a favorable reorganization of the solvent for the folding reaction. We begin by discussing the effect of electrostatic charge on solvent-mediated hydrophobic forces in an aqueous environment. Based on these initial physical arguments, we construct a simple, phenomenological theory for the thermodynamics of density and hydrogen bond order fluctuations in liquid water. Within the framework of this model, we investigate the effect of confinement within a chaperonin-like cavity on the configurational free energy of water by calculating solvent free energies for cavities corresponding to the different conformational states in the ATP- driven catalytic cycle of the prokaryotic chaperonin GroEL. Our findings suggest that one function of chaperonins may be to trap unfolded proteins and subsequently expose them to a micro-environment in which the hydrophobic effect, a crucial thermodynamic driving force for folding, is enhanced.
England Jeremy L.
Pande Vijay S.
No associations
LandOfFree
Potential for modulation of the hydrophobic effect inside chaperonins does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Potential for modulation of the hydrophobic effect inside chaperonins, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Potential for modulation of the hydrophobic effect inside chaperonins will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-45206