PMID- 31149826
OWN - NLM
STAT- MEDLINE
DCOM- 20200717
LR  - 20200717
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 123
IP  - 23
DP  - 2019 Jun 13
TI  - Electrostatic Influence on Photoisomerization in Bacteriorhodopsin and 
      Halorhodopsin.
PG  - 4850-4857
LID - 10.1021/acs.jpcb.9b01837 [doi]
AB  - Bacteriorhodopsin (bR) and halorhodopsin (hR) are both membrane proteins that 
      transport ions across the cell membrane in halobacteria. Their ion transport 
      function is triggered by photoactivated isomerization of the retinal protonated 
      Schiff base (RPSB) chromophore. In spite of their similar structures, bR and hR 
      exhibit widely differing RPSB isomerization rates and quantum yields (with bR 
      being both faster and more efficient than hR). Previous simulations of 
      photoisomerization in bR and hR using ab initio multiple spawning (AIMS) with 
      QM/MM have successfully reproduced the experimentally observed ordering of 
      quantum yields and isomerization rates, but the origin of these differences 
      remains elusive. Here we investigate the role of electrostatic interactions in 
      the protein pocket surrounding RPSB. We probe the influence of protein 
      electrostatics by modifying the charge of the complex counterion in bR/hR to be 
      more/less negative than the native state. We find that such modifications lead to 
      bR-like behavior in hR and vice versa. This demonstrates the crucial role of 
      electrostatic interactions in controlling the outcome of RPSB photoisomerization.
FAU - Punwong, C
AU  - Punwong C
AD  - Department of Physics, Faculty of Science , Prince of Songkla University , 
      Songkhla 90112 Thailand.
FAU - Hannongbua, S
AU  - Hannongbua S
AD  - Department of Chemistry, Faculty of Science , Chulalongkorn University , Bangkok 
      10330 , Thailand.
FAU - Martinez, T J
AU  - Martinez TJ
AUID- ORCID: 0000-0002-4798-8947
AD  - Department of Chemistry and the PULSE Institute , Stanford University , Stanford 
      , California 94305 , United States.
AD  - SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United 
      States.
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 - 20190531
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
RN  - 0 (Halorhodopsins)
RN  - 53026-44-1 (Bacteriorhodopsins)
SB  - IM
MH  - Bacteriorhodopsins/*chemistry
MH  - Halorhodopsins/*chemistry
MH  - Molecular Dynamics Simulation
MH  - Photochemical Processes
MH  - Protein Conformation
MH  - Quantum Theory
MH  - Static Electricity
MH  - Stereoisomerism
MH  - Thermodynamics
EDAT- 2019/06/01 06:00
MHDA- 2020/07/18 06:00
CRDT- 2019/06/01 06:00
PHST- 2019/06/01 06:00 [pubmed]
PHST- 2020/07/18 06:00 [medline]
PHST- 2019/06/01 06:00 [entrez]
AID - 10.1021/acs.jpcb.9b01837 [doi]
PST - ppublish
SO  - J Phys Chem B. 2019 Jun 13;123(23):4850-4857. doi: 10.1021/acs.jpcb.9b01837. Epub 
      2019 May 31.