title: Real-time submillisecond single-molecule FRET dynamics of freely diffusing molecules with liposome tethering.
abstract: Single-molecule fluorescence resonance energy transfer (smFRET) is one of the powerful techniques for deciphering the dynamics of unsynchronized biomolecules. However, smFRET is limited in its temporal resolution for observing dynamics. Here, we report a novel method for observing real-time dynamics with submillisecond resolution by tethering molecules to freely diffusing 100-nm-sized liposomes. The observation time for a diffusing molecule is extended to 100 ms with a submillisecond resolution, which allows for direct analysis of the transition states from the FRET time trace using hidden Markov modelling. We measure transition rates of up to 1,500 s(-1) between two conformers of a Holliday junction. The rapid diffusional migration of Deinococcus radiodurans single-stranded DNA-binding protein (SSB) on single-stranded DNA is resolved by FRET, faster than that of Escherichia coli SSB by an order of magnitude. Our approach is a powerful method for studying the dynamics and movements of biomolecules at submillisecond resolution.
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Jae-Yeol
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Cheolhee
authors.initials: C
authors.lastname: Kim
authors.affiliation: 1] Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea [2] School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Nam Ki
authors.initials: NK
authors.lastname: Lee
mesh_terms: D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D034301:Deinococcus; D004058:Diffusion; D004926:Escherichia coli; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008081:Liposomes; D036103:Nanotechnology / Q000379:methods*; D017785:Photons
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D008081:Liposomes