Shrinking gate fluorescence correlation spectroscopy yields equilibrium constants and separates photophysics from structural dynamics.

ABSTRACT: Fluorescence correlation spectroscopy is a versatile tool for studying fast conformational changes of biomolecules especially when combined with Förster resonance energy transfer (FRET). Despite the many methods available for identifying structural dynamics in FRET experiments, the determination of the forward and backward transition rate constants and thereby also the equilibrium constant is difficult when two intensity levels are involved. Here, we combine intensity correlation analysis with fluorescence lifetime information by including only a subset of photons in the autocorrelation analysis based on their arrival time with respect to the excitation pulse (microtime). By fitting the correlation amplitude as a function of microtime gate, the transition rate constants from two fluorescen

SUBMITTER: Schroder T 

PROVIDER: S-EPMC9942831 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature