Spot variation fluorescence correlation spectroscopy allows for superresolution chronoscopy of confinement times in membranes Journal Article


Author(s): Ruprecht, Verena; Wieser, Stefan; Marguet, Didier; Schuetz, Gerhard J
Article Title: Spot variation fluorescence correlation spectroscopy allows for superresolution chronoscopy of confinement times in membranes
Affiliation
Abstract: Resolving the dynamical interplay of proteins and lipids in the live-cell plasma membrane represents a central goal in current cell biology. Superresolution concepts have introduced a means of capturing spatial heterogeneity at a nanoscopic length scale. Similar concepts for detecting dynamical transitions (superresolution chronoscopy) are still lacking. Here, we show that recently introduced spot-variation fluorescence correlation spectroscopy allows for sensing transient confinement times of membrane constituents at dramatically improved resolution. Using standard diffraction-limited optics, spot-variation fluorescence correlation spectroscopy captures signatures of single retardation events far below the transit time of the tracer through the focal spot. We provide an analytical description of special cases of transient binding of a tracer to pointlike traps, or association of a tracer with nanodomains. The influence of trap mobility and the underlying binding kinetics are quantified. Experimental approaches are suggested that allow for gaining quantitative mechanistic insights into the interaction processes of membrane constituents.
Keywords: Time Factors; Kinetics; Stochastic Processes; Monte Carlo Method; Cell Membrane/metabolism; Diffusion; Spectrometry, Fluorescence/methods
Journal Title: Biophysical Journal
Volume: 100
Issue 11
ISSN: 1542-0086
Publisher: Biophysical Society  
Date Published: 2011-06-08
Start Page: 2839
End Page: 2845
Copyright Statement: CC-BY-NC-ND 3.0
Sponsor: Y 250-B03/Austrian Science Fund FWF/Austria
DOI: 10.1016/j.bpj.2011.04.035
Open access: yes (OA journal)