Energy Transfer Observed in Live Cells Using Two-Dimensional Electronic Spectroscopy.
Two-dimensional electronic spectroscopy (2DES) elucidates electronic structure and dynamics on a femtosecond time scale and has proven to be an incisive tool for probing congested linear spectra of biological systems. However, samples that scatter light intensely frustrate 2DES analysis, necessitating the use of isolated protein chromophore complexes when studying photosynthetic energy transfer processes. We present a method for conducting 2DES experiments that takes only seconds to acquire thousands of 2DES spectra and permits analysis of highly scattering samples, specifically whole cells of the purple bacteriumRhodobacter sphaeroides.Thesein vivo2DES experiments reveal similar timescales for energy transfer within the antennae complex (light harvesting complex 2, LH2) both in the native photosynthetic membrane environment and in isolated detergent micelles.
Graduate Program in the Biophysical Sciences, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago, Chicago, IL 60637.
Peter D
PD
Dahlberg
Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago, Chicago, IL, 60637.
Andrew F
AF
Fidler
Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago, Chicago, IL, 60637.
Justin R
JR
Caram
Graduate Program in the Biophysical Sciences, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago, Chicago, IL 60637.
Phillip D
PD
Long
Department of Chemistry, Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago, Chicago, IL, 60637.
Gregory S
GS
Engel
Nonlinear Spectroscopy; Photosynthesis; Ultrafast Dynamics