Identification of the Proton Pathway in Bacterial Reaction Centers:  Decrease of Proton Transfer Rate by Mutation of Surface Histidines at H126 and H128 and Chemical Rescue by Imidazole Identifies the Initial Proton Donors†

Biochemistry ◽  
2001 ◽  
Vol 40 (48) ◽  
pp. 14538-14546 ◽  
Author(s):  
Pia Ädelroth ◽  
Mark L. Paddock ◽  
Ali Tehrani ◽  
J. Thomas Beatty ◽  
George Feher ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Transfer Rate ◽  
Reaction Centers ◽  
Chemical Rescue ◽  
Bacterial Reaction Centers ◽  
Proton Donors

Determination of Proton Transfer Rates by Chemical Rescue:  Application to Bacterial Reaction Centers†

Biochemistry ◽  
2002 ◽  
Vol 41 (50) ◽  
pp. 14716-14725 ◽  
Author(s):  
M. L. Paddock ◽  
P. Ädelroth ◽  
G. Feher ◽  
M. Y. Okamura ◽  
J. T. Beatty
Keyword(s):  
Proton Transfer ◽  
Reaction Centers ◽  
Transfer Rates ◽  
Chemical Rescue ◽  
Bacterial Reaction Centers

Pathway of Proton Transfer in Bacterial Reaction Centers: Role of Aspartate-L213 in Proton Transfers Associated with Reduction of Quinone to Dihydroquinone

Biochemistry ◽  
1994 ◽  
Vol 33 (3) ◽  
pp. 734-745 ◽  
Author(s):  
M. L. Paddock ◽  
S. H. Rongey ◽  
P. H. McPherson ◽  
A. Juth ◽  
G. Feher ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Reaction Centers ◽  
Bacterial Reaction Centers ◽  
Proton Transfers

scholarly journals Proton transfer pathways and mechanism in bacterial reaction centers

FEBS Letters ◽  
2003 ◽  
Vol 555 (1) ◽  
pp. 45-50 ◽  
Author(s):  
M.L. Paddock ◽  
G. Feher ◽  
M.Y. Okamura
Keyword(s):  
Proton Transfer ◽  
Reaction Centers ◽  
Bacterial Reaction Centers

scholarly journals Determination of the binding sites of the proton transfer inhibitors Cd2+ and Zn2+ in bacterial reaction centers

2000 ◽  
Vol 97 (4) ◽  
pp. 1542-1547 ◽  
Author(s):  
H. L. Axelrod ◽  
E. C. Abresch ◽  
M. L. Paddock ◽  
M. Y. Okamura ◽  
G. Feher
Keyword(s):  
Proton Transfer ◽  
Binding Sites ◽  
Reaction Centers ◽  
Bacterial Reaction Centers

Proton Transfer in Bacterial Reaction Centers and Bacteriorhodopsin in the Presence of Dipyridamole

2001 ◽  
Vol 26 (2-3) ◽  
pp. 287-299 ◽  
Author(s):  
P.P. Knox ◽  
E.P. Lukashev ◽  
M.D. Mamedov ◽  
A. Yu. Semenov ◽  
G.P. Borissevitch
Keyword(s):  
Proton Transfer ◽  
Reaction Centers ◽  
Bacterial Reaction Centers

scholarly journals Pathway of proton transfer in bacterial reaction centers: replacement of glutamic acid 212 in the L subunit by glutamine inhibits quinone (secondary acceptor) turnover

1989 ◽  
Vol 86 (17) ◽  
pp. 6602-6606 ◽  
Author(s):  
M L Paddock ◽  
S H Rongey ◽  
G Feher ◽  
M Y Okamura
Keyword(s):  
Electron Transfer ◽  
Proton Transfer ◽  
Transfer Rate ◽  
Ph Dependence ◽  
Proton Donor ◽  
Reaction Centers ◽  
Site Directed Mutagenesis ◽  
Back Reaction ◽  
Electron Transfer Rate

The mechanism of proton transfer in the reaction centers (RCs) from Rhodobacter sphaeroides was investigated by site-directed mutagenesis. Replacement of Glu-212 of the L subunit, a protonatable residue located near the secondary acceptor (QB) binding site, by glutamine reduced the in vitro electron turnover from cytochrome c to 2,3-dimethoxy-5-methylbenzoquinone (UQ0) by a factor of 25. The electron transfer rate to QB remained essentially unimpaired. Consequently, it is postulated that the reduced turnover in the mutant is due to a reduced rate of proton transfer to QB2-. The lack of pH dependence of the forward electron transfer rate DQA-QB----DQAQB- and the back reaction rate D+QAQB- ----DQAQB (where D = primary donor and QA = primary acceptor) in the mutant RC indicate that the observed pH dependence in the native RC is due to Glu-212, which has an anomalously high pKa value of 9.5 +/- 0.3. These results support the involvement of Glu-212 as a proton donor to reduced QB.

In Bacterial Reaction Centers, a Key Residue Suppresses Mutational Blockage of Two Different Proton Transfer Steps†

Biochemistry ◽  
1998 ◽  
Vol 37 (8) ◽  
pp. 2077-2083 ◽  
Author(s):  
Jaroslava Miksovska ◽  
Marie Valerio-Lepiniec ◽  
Marianne Schiffer ◽  
Deborah K. Hanson ◽  
Pierre Sebban
Keyword(s):  
Proton Transfer ◽  
Reaction Centers ◽  
Bacterial Reaction Centers
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