Viscosity dependence of the folding kinetics of a dimeric and monomeric coiled coil.


Abstract

We measured whether solvent viscosity, and hence chain diffusion, plays a role in the rate-limiting step of the folding reactions of GCN4-p2', a simple alpha-helical coiled coil derived from the leucine zipper region of bZIP transcriptional activator GCN4. To deconvolute the dual effects of viscosogenic solvents on both viscosity, eta, and stability, earlier attempts assumed that the cosolvent and denaturant interact to the same degree in the transition state. Applying this analysis to GCN4-p2' yielded a nearly 1/eta dependence between folding rates and viscosity for both the dimeric and the cross-linked, monomeric versions of the coiled coil, but it revealed no such coherent relationship for cytochrome c. We also developed a method to determine the relative viscosity dependence of the dimeric and monomeric forms of the coiled coil independent of the assumption concerning the transition state's relative interaction with cosolvents and denaturants. Application of this method indicated that the effect of viscosity on both the folding and the unfolding rates was the same for the dimeric and monomeric versions, further supporting the view that the folding of the dimeric version is folding-limited rather than encounter-limited. The finding that GCN4-p2' folding appears to exhibit a 1/eta viscosity dependence implies that the rate-limiting step in folding is opposed predominantly by solvent-derived rather than internal frictional forces. These results are interpreted in relation to various models for protein folding. Study holds ProTherm entries: 16362, 16363, 16364, 16365, 16366, 16367, 16368, 16369, 16370, 16371, 16372, 16373, 16374, 16375, 16376 Extra Details: alpha-helical coiled coil from leucine zipper region, dimeric. equilibrium. GCN4-p2, cytochrome c, folding kinetics, transcriptional activator

Submission Details

ID: zBqP2Xsy3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:47 p.m.

Version: 1

Publication Details
Bhattacharyya RP;Sosnick TR,Biochemistry (1999) Viscosity dependence of the folding kinetics of a dimeric and monomeric coiled coil. PMID:10029555
Additional Information

Number of data points 30
Proteins Cytochrome c ; General control protein GCN4 ; General control protein GCN4 ; Cytochrome c
Unique complexes 2
Assays/Quantities/Protocols Experimental Assay: m buffers:Imidazole: 50 mM, pH:7.0, prot_conc:10-20 micro M, details:Additives Glycerol(25% (w/w)), ; Experimental Assay: dG_H2O buffers:Imidazole: 50 mM, pH:7.0, prot_conc:10-20 micro M, details:Additives Glycerol(25% (w/ ; Experimental Assay: m buffers:Imidazole: 50 mM, pH:7.0, prot_conc:10-20 micro M, details:Additives Glucose(21% (w/w)), ; Experimental Assay: dG_H2O buffers:Imidazole: 50 mM, pH:7.0, prot_conc:10-20 micro M, details:Additives Glucose(21% (w/w ; Experimental Assay: m buffers:Imidazole: 50 mM, details:Additives Ethylene glycol(27% (w/w)),, prot_conc:10-20 micro M, ; Experimental Assay: dG_H2O buffers:Imidazole: 50 mM, details:Additives Ethylene glycol(27% (w/w)),, prot_conc:10-20 micr ; Experimental Assay: m buffers:Imidazole: 50 mM, details:Additives , prot_conc:10-20 micro M, pH:7.0 ; Experimental Assay: dG_H2O buffers:Imidazole: 50 mM, details:Additives , prot_conc:10-20 micro M, pH:7.0 ; Experimental Assay: m prot_conc:34.1 micro M, buffers:Sodium acetate: 20 mM, pH:5.5, details:Additives glycerol (9%), ; Experimental Assay: dG_H2O prot_conc:34.1 micro M, buffers:Sodium acetate: 20 mM, pH:5.5, details:Additives glycerol (9% ; Experimental Assay: m buffers:Sodium acetate: 20 mM, pH:5.5, prot_conc:2-10 micro M, details:Additives glycerol (15.2%), ; Experimental Assay: dG_H2O buffers:Sodium acetate: 20 mM, pH:5.5, prot_conc:2-10 micro M, details:Additives glycerol (15 ; Experimental Assay: m prot_conc:34.1 micro M, buffers:Sodium acetate: 20 mM, pH:5.5, details:Additives glycerol (15.2%), ; Experimental Assay: dG_H2O prot_conc:34.1 micro M, buffers:Sodium acetate: 20 mM, pH:5.5, details:Additives glycerol (15 ; Experimental Assay: m buffers:Sodium acetate: 20 mM, pH:5.5, prot_conc:2-10 micro M, details:Additives glycerol (9%), ; Experimental Assay: dG_H2O buffers:Sodium acetate: 20 mM, pH:5.5, prot_conc:2-10 micro M, details:Additives glycerol (9% ; Experimental Assay: m buffers:Sodium acetate: 20 mM, pH:5.5, details:Additives , prot_conc:2-10 micro M ; Experimental Assay: dG_H2O buffers:Sodium acetate: 20 mM, pH:5.5, details:Additives , prot_conc:2-10 micro M ; Experimental Assay: m prot_conc:34.1 micro M, details:Additives , buffers:Sodium acetate: 20 mM, pH:5.5 ; Experimental Assay: dG_H2O prot_conc:34.1 micro M, details:Additives , buffers:Sodium acetate: 20 mM, pH:5.5
Libraries Mutations for sequence GDVEKGKKIFVQKCAQCHTVEKGGKHKTGPNLHGLFGRKTGQAPGFTYTDANKNKGITWKEETLMEYLENPKKYIPGTKMIFAGIKKKTEREDLIAYLKKATNE ; Mutations for sequence RMKQLEDKVEELLSKNYHLENEVARLKKLVGER
Sequence Assay Result Units