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Slowing Down Downhill Folding: a Three-probe Study

Overview
Journal Biophys J
Publisher Cell Press
Specialty Biophysics
Date 2009 Jul 8
PMID 19580767
Citations 14
Authors
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Abstract

The mutant Tyr22Trp/Glu33Tyr/Gly46Ala/Gly48Ala of lambda repressor fragment lambda(6-85) was previously assigned as an incipient downhill folder. We slow down its folding in a cryogenic water-ethylene-glycol solvent (-18 to -28 degrees C). The refolding kinetics are probed by small-angle x-ray scattering, circular dichroism, and fluorescence to measure the radius of gyration, the average secondary structure content, and the native packing around the single tryptophan residue. The main resolved kinetic phase of the mutant is probe independent and faster than the main phase observed for the pseudo-wild-type. Excess helical structure formed early on by the mutant may reduce the formation of turns and prevent the formation of compact misfolded states, speeding up the overall folding process. Extrapolation of our main cryogenic folding phase and previous T-jump measurements to 37 degrees C yields nearly the same refolding rate as extrapolated by Oas and co-workers from NMR line-shape data. Taken together, all the data consistently indicate a folding speed limit of approximately 4.5 micros for this fast folder.

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References
1.
Sadqi M, Lapidus L, Munoz V . How fast is protein hydrophobic collapse?. Proc Natl Acad Sci U S A. 2003; 100(21):12117-22. PMC: 218722. DOI: 10.1073/pnas.2033863100. View

2.
Gruebele M . Comment on Probe-dependent and nonexponential relaxation kinetics: unreliable signatures of downhill protein folding. Proteins. 2007; 70(3):1099-102. DOI: 10.1002/prot.21789. View

3.
Kuwata K, Shastry R, Cheng H, Hoshino M, Batt C, Goto Y . Structural and kinetic characterization of early folding events in beta-lactoglobulin. Nat Struct Biol. 2001; 8(2):151-5. DOI: 10.1038/84145. View

4.
Bryngelson J, Onuchic J, Socci N, Wolynes P . Funnels, pathways, and the energy landscape of protein folding: a synthesis. Proteins. 1995; 21(3):167-95. DOI: 10.1002/prot.340210302. View

5.
Kim S, Dumont C, Gruebele M . Simulation-based fitting of protein-protein interaction potentials to SAXS experiments. Biophys J. 2008; 94(12):4924-31. PMC: 2397344. DOI: 10.1529/biophysj.107.123240. View