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Tuning the redox potential of the primary electron donor in bacterial reaction centers by manganese binding and light-induced structural changes.

Author(s): Deshmukh SS, Kálmán L

Biochim Biophys Acta Bioenerg. 2020 Aug 07;:148285 Authors: Deshmukh SS, Kálmán L

Article GUID: 32777306
Bound detergent molecules in bacterial reaction centers facilitate detection of tetryl explosive.

Author(s): Modafferi D, Zazubovich V, Kálmán L

Photosynth Res. 2020 Jul 06;: Authors: Modafferi D, Zazubovich V, Kálmán L

Article GUID: 32632533
Proton release due to manganese binding and oxidation in modified bacterial reaction centers.

Author(s): Kálmán L, Thielges MC, Williams JC, Allen JP

Biochemistry. 2005 Oct 11;44(40):13266-73 Authors: Kálmán L, Thielges MC, Williams JC, Allen JP

Article GUID: 16201752
Comparison of bacterial reaction centers and photosystem II.

Author(s): Kálmán L, Williams JC, Allen JP

Photosynth Res. 2008 Oct-Dec;98(1-3):643-55 Authors: Kálmán L, Williams JC, Allen JP

Article GUID: 18853275
Effect of anions on the binding and oxidation of divalent manganese and iron in modified bacterial reaction centers.

Author(s): Tang K, Williams JC, Allen JP, Kálmán L

Biophys J. 2009 Apr 22;96(8):3295-304 Authors: Tang K, Williams JC, Allen JP, Kálmán L

Article GUID: 19383473
Light-induced conformational changes in photosynthetic reaction centers: dielectric relaxation in the vicinity of the dimer.

Author(s): Deshmukh SS, Williams JC, Allen JP, Kálmán L

Biochemistry. 2011 Jan 25;50(3):340-8 Authors: Deshmukh SS, Williams JC, Allen JP, Kálmán L

Article GUID: 21141811
Light-induced conformational changes in photosynthetic reaction centers: redox-regulated proton pathway near the dimer.

Author(s): Deshmukh SS, Williams JC, Allen JP, Kálmán L

Biochemistry. 2011 Apr 26;50(16):3321-31 Authors: Deshmukh SS, Williams JC, Allen JP, Kálmán L

Article GUID: 21410139
Light-induced conformational changes in photosynthetic reaction centers: impact of detergents and lipids on the electronic structure of the primary electron donor.

Author(s): Deshmukh SS, Akhavein H, Williams JC, Allen JP, Kalman L

Biochemistry. 2011 Jun 14;50(23):5249-62 Authors: Deshmukh SS, Akhavein H, Williams JC, Allen JP, Kalman L

Article GUID: 21561160
Lipid binding to the carotenoid binding site in photosynthetic reaction centers.

Author(s): Deshmukh SS, Tang K, Kálmán L

J Am Chem Soc. 2011 Oct 12;133(40):16309-16 Authors: Deshmukh SS, Tang K, Kálmán L

Article GUID: 21894992
The interaction of streptococcal enolase with canine plasminogen: the role of surfaces in complex formation.

Author(s): Balhara V, Deshmukh SS, Kálmán L, Kornblatt JA

PLoS One. 2014;9(2):e88395 Authors: Balhara V, Deshmukh SS, Kálmán L, Kornblatt JA

Article GUID: 24520380
Low potential manganese ions as efficient electron donors in native anoxygenic bacteria.

Author(s): Deshmukh SS, Protheroe C, Ivanescu MA, Lag S, Kálmán L

Biochim Biophys Acta Bioenerg. 2018 Apr;1859(4):227-233 Authors: Deshmukh SS, Protheroe C, Ivanescu MA, Lag S, Kálmán L

Article GUID: 29355486
Title:Light-induced conformational changes in photosynthetic reaction centers: redox-regulated proton pathway near the dimer.
Authors:Deshmukh SS,  Williams JC,  Allen JP,  Kálmán L
Link:https://www.ncbi.nlm.nih.gov/pubmed/21410139?dopt=Abstract
Category:Biochemistry
PMID:21410139
Dept Affiliation: PHYSICS
1 Department of Physics, Concordia University, Montreal, Quebec H4B 1R6, Canada.

Description:

Light-induced conformational changes in photosynthetic reaction centers: redox-regulated proton pathway near the dimer.

Biochemistry. 2011 Apr 26;50(16):3321-31

Authors: Deshmukh SS, Williams JC, Allen JP, Kálmán L

Abstract

The influence of the hydrogen bonds on the light-induced structural changes were studied in the wild type and 11 mutants with different hydrogen bonding patterns of the primary electron donor of reaction centers from Rhodobacter sphaeroides. Previously, using the same set of mutants at pH 8, a marked light-induced change of the local dielectric constant in the vicinity of the dimer was reported in wild type and in mutants retaining Leu L131 that correlated with the recovery kinetics of the charge-separated state [ Deshmukh et al. (2011) Biochemistry, 50, 340-348]. In this work after prolonged illumination the recovery of the oxidized dimer was found to be multiphasic in all mutants. The fraction of the slowest phase, assigned to a recovery from a conformationally altered state, was strongly pH dependent and found to be extremely long at room temperature, at pH 6, with rate constants of ~10(-3) s(-1). In wild type and in mutants with Leu at L131 the very long recovery kinetics was coupled to a large proton release at pH 6 and a decrease of up to 79 mV of the oxidation potential of the dimer. In contrast, in the mutants carrying the Leu to His mutation at the L131 position, only a negligible fraction of the dimer exhibited lowered potential, the large proton release was not observed, the oxidized dimer recovered 1 or 2 orders of magnitude faster depending on the pH, and the very long-lived state was not or barely detectable. These results are modeled as arising from the loss of a proton pathway from the bacteriochlorophyll dimer to the solvent when His is present at the L131 position.

PMID: 21410139 [PubMed - indexed for MEDLINE]