II. Kinetic pathways of switching optical conformations in DsRed by 2D Fourier imaging correlation spectroscopy.
The kinetics of biomolecular conformational transitions can be studied by two-dimensional (2D) magnetic resonance and optical spectroscopic methods. Here we apply polarization-modulated Fourier imaging correlation spectroscopy (PM-FICS) to demonstrate a new approach to 2D optical spectroscopy. PM-FICS enables measurements of conformational fluctuations of fluorescently labeled macromolecules on a broad range of time scales (10(-3)-10(2) s). We examine the optical switching pathways of DsRed, a tetrameric complex of fluorescent protein subunits. An analysis of PM-FICS coordinate trajectories, in terms of 2D spectra and joint probability distributions, provides detailed information about the transition pathways between distinct dipole-coupled DsRed conformations.
Senning
Eric N
EN
Department of Chemistry, University of Oregon, Eugene, Oregon 97403, USA.
Lott
Geoffrey A
GA
Fink
Michael C
MC
Marcus
Andrew H
AH
D000818:Animals; D003116:Color; D005583:Fourier Analysis; D007700:Kinetics; D008164:Luminescent Proteins / Q000737:chemistry*; D008968:Molecular Conformation; D055620:Optical Phenomena; D013057:Spectrum Analysis
D008164:Luminescent Proteins; C413663:fluorescent protein 583