PMID- 23140223
OWN - NLM
STAT- MEDLINE
DCOM- 20131204
LR  - 20130426
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 117
IP  - 16
DP  - 2013 Apr 25
TI  - Probing ultrafast photochemistry of retinal proteins in the near-IR: 
      bacteriorhodopsin and anabaena sensory rhodopsin vs retinal protonated Schiff 
      base in solution.
PG  - 4670-9
LID - 10.1021/jp309189y [doi]
AB  - Photochemistry of bacteriorhodopsin (bR), anabaena sensory rhodopsin (ASR), and 
      all-trans retinal protonated Schiff base (RPSB) in ethanol is followed with 
      femtosecond pump-hyperspectral near-IR (NIR) probe spectroscopy. This is the 
      first systematic probing of retinal protein photochemistry in this spectral 
      range. Stimulated emission of the proteins is demonstrated to extend deep into 
      the NIR, and to decay on the same characteristic time scales previously 
      determined by visible probing. No signs of a transient NIR absorption band above 
      lambdapr > 1.3 mum, which was recently reported and is verified here for the RPSB in 
      solution, is observed in either protein. This discrepancy demonstrates that the 
      protein surroundings change photochemical traits of the chromophore 
      significantly, inducing changes either in the energies or couplings of 
      photochemically relevant electronic excited states. In addition, low-frequency 
      and heavily damped spectral modulations are observed in the NIR signals of all 
      three systems up to 1.4 mum. By background subtraction and Fourier analysis they 
      are shown to resemble wave packet signatures in the visible, stemming from 
      multiple vibrational modes and by analogy are assigned to torsional wave packets 
      in the excited state of the retinal chromophore. Differences in the vibrational 
      frequencies between the three samples and the said discrepancy in transient 
      spectra are discussed in terms of opsin effects on the RPSB electronic structure.
FAU - Wand, Amir
AU  - Wand A
AD  - Institute of Chemistry and the Farkas Center for Light-Induced Processes, The 
      Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 
      91904, Israel.
FAU - Loevsky, Boris
AU  - Loevsky B
FAU - Friedman, Noga
AU  - Friedman N
FAU - Sheves, Mordechai
AU  - Sheves M
FAU - Ruhman, Sanford
AU  - Ruhman S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20121126
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
RN  - 0 (Eye Proteins)
RN  - 0 (Protons)
RN  - 0 (Schiff Bases)
RN  - 0 (Sensory Rhodopsins)
RN  - 0 (Solutions)
RN  - 53026-44-1 (Bacteriorhodopsins)
SB  - IM
MH  - Anabaena/*metabolism
MH  - Bacteriorhodopsins/*chemistry/metabolism
MH  - Eye Proteins/*chemistry/metabolism
MH  - Fourier Analysis
MH  - Isomerism
MH  - Protons
MH  - Schiff Bases/*chemistry
MH  - Sensory Rhodopsins/*chemistry/metabolism
MH  - Solutions/chemistry
MH  - Spectroscopy, Near-Infrared
EDAT- 2012/11/13 06:00
MHDA- 2013/12/16 06:00
CRDT- 2012/11/13 06:00
PHST- 2012/11/13 06:00 [entrez]
PHST- 2012/11/13 06:00 [pubmed]
PHST- 2013/12/16 06:00 [medline]
AID - 10.1021/jp309189y [doi]
PST - ppublish
SO  - J Phys Chem B. 2013 Apr 25;117(16):4670-9. doi: 10.1021/jp309189y. Epub 2012 Nov 
      26.