title: Ultrafast dynamics of protein collapse from single-molecule photon statistics.
abstract: We use the statistics of photon emission from single molecules to probe the ultrafast dynamics of an unfolded protein via Förster resonance energy transfer. Global reconfiguration of the chain occurs on a time scale of approximately equal to 50 ns and slows down concomitant with chain collapse under folding conditions. These diffusive dynamics provide a missing link between the phenomenological chemical kinetics commonly used in protein folding and a physical description in terms of quantitative free energy surfaces. The experiments demonstrate the potential of single-molecule methods in accessing the biologically important nanosecond time scales even in heterogeneous populations.
authors.affiliation: *Biochemisches Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Nettels
authors.forename: Irina V
authors.initials: IV
authors.lastname: Gopich
authors.forename: Armin
authors.initials: A
authors.lastname: Hoffmann
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schuler
mesh_terms: D031541:Fluorescence Resonance Energy Transfer; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D017785:Photons; D011489:Protein Denaturation; D017510:Protein Folding; D013816:Thermodynamics; D020124:Thermotoga maritima / Q000378:metabolism*
chemical_list: D006360:Heat-Shock Proteins; D010455:Peptides