Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 2007 | Supplemental Material + Published
Journal Article Open

Ultrafast light-induced response of photoactive yellow protein chromophore analogues


The fluorescence decays of several analogues of the photoactive yellow protein (PYP) chromophore in aqueous solution have been measured by femtosecond fluorescence up-conversion and the corresponding time-resolved fluorescence spectra have been reconstructed. The native chromophore of PYP is a thioester derivative of p-coumaric acid in its trans deprotonated form. Fluorescence kinetics are reported for a thioester phenyl analogue and for two analogues where the thioester group has been changed to amide and carboxylate groups. The kinetics are compared to those we previously reported for the analogues bearing ketone and ester groups. The fluorescence decays of the full series are found to lie in the 1–10 ps range depending on the electron-acceptor character of the substituent, in good agreement with the excited-state relaxation kinetics extracted from transient absorption measurements. Steady-state photolysis is also examined and found to depend strongly on the nature of the substituent. While it has been shown that the ultrafast light-induced response of the chromophore in PYP is controlled by the properties of the protein nanospace, the present results demonstrate that, in solution, the relaxation dynamics and pathway of the chromophore is controlled by its electron donor–acceptor structure: structures of stronger electron donor–acceptor character lead to faster decays and less photoisomerisation.

Additional Information

This journal is © The Royal Society of Chemistry and Owner Societies 2007. Received 22nd January 2007, Accepted 29th March 2007. First published on the web 18th April 2007. The authors thank Jean-Bernard Baudin and Ludovic Jullien for providing pCMH, pCEH and pCTH which were synthesized in their group. MMM thanks Albert M. Brouwer for helpful suggestions. This collaborative work was done within the framework of a Blaise Pascal Chair AHZ was awarded at the Department of Chemistry of the Ecole Normale Supérieure (ENS) in Paris. Financial support from the ENS Foundation is acknowledged. AE is grateful to Caltech for a Graduate Fellowship during her stay in Pasadena. Electronic supplementary information (ESI) available: Steady-state absorption and fluorescence spectra of PYP chromophore analogues (Fig. S1). See DOI: 10.1039/b700927e

Attached Files

Published - ESPpps07.pdf

Supplemental Material - ESPpps07suppspectra.pdf


Files (410.8 kB)
Name Size Download all
8.4 kB Preview Download
267.8 kB Preview Download
9.9 kB Preview Download
122.9 kB Preview Download
1.8 kB Preview Download

Additional details

August 22, 2023
October 16, 2023