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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
Title:Proton release due to manganese binding and oxidation in modified bacterial reaction centers.
Authors:Kálmán L,  Thielges MC,  Williams JC,  Allen JP
Link:https://www.ncbi.nlm.nih.gov/pubmed/16201752?dopt=Abstract
Category:Biochemistry
PMID:16201752
Dept Affiliation: PHYSICS
1 Department of Physics, Concordia University, Montreal, Quebec H4B 1R6, Canada.

Description:

Proton release due to manganese binding and oxidation in modified bacterial reaction centers.

Biochemistry. 2005 Oct 11;44(40):13266-73

Authors: Kálmán L, Thielges MC, Williams JC, Allen JP

Abstract

The pH dependence of binding and oxidation of Mn2+ in highly oxidizing reaction centers with designed metal-binding sites was characterized by light-minus-dark optical difference spectroscopy and direct measurements of proton uptake/release. These mutants bind a Mn2+ ion that can efficiently transfer an electron to the oxidized bacteriochlorophyll dimer, as described earlier [Thielges et al. (2005) Biochemistry 44, 7389-7394]. The dissociation constant, KD, significantly increased with decreasing pH. The pH dependence of KD between pH 7 and pH 8 was consistent with the binding of Mn2+ being stabilized by the electrostatic release of two protons. The strong pH dependence of proton release upon Mn2+ binding, with a maximal release of 1.4 H+ per reaction center, was interpreted as being a result of a shift in the pKa values of the coordinating residues and possibly other nearby residues. A small amount of proton release associated with Mn2+ oxidation was observed upon illumination. These results show that functional metal-binding sites can be incorporated into proteins upon consideration of both the metal coordination and protonation states of the ligands.

PMID: 16201752 [PubMed - indexed for MEDLINE]