Tuning of the redox potential of the primary electron donor in reaction centres of purple bacteria: effects of amino acid polarity and position

FEBS Letters ◽  
2002 ◽  
Vol 527 (1-3) ◽  
pp. 171-175 ◽  
Author(s):  
Diane Spiedel ◽  
Michael R Jones ◽  
Bruno Robert
Keyword(s):  
Amino Acid ◽  
Redox Potential ◽  
Electron Donor ◽  
Purple Bacteria ◽  
Primary Electron ◽  
Primary Electron Donor ◽  
Reaction Centres ◽  
Amino Acid Polarity

scholarly journals Redox interaction of Mn–bicarbonate complexes with reaction centres of purple bacteria

2007 ◽  
Vol 363 (1494) ◽  
pp. 1245-1251 ◽  
Author(s):  
A.A Khorobrykh ◽  
V.V Terentyev ◽  
S.K Zharmukhamedov ◽  
V.V Klimov
Keyword(s):  
Experimental Evidence ◽  
Electron Donor ◽  
Rhodobacter Sphaeroides ◽  
Purple Bacteria ◽  
Primary Electron ◽  
Oxygenic Photosynthesis ◽  
Primary Electron Donor ◽  
Bicarbonate Concentration ◽  
Reaction Centres ◽  
Redox Interaction

It is found that dark reduction of photooxidized primary electron donor P 870 + in reaction centres from purple anoxygenic bacteria (two non-sulphur Fe-oxidizing Rhodovulum iodosum and Rhodovulum robiginosum , Rhodobacter sphaeroides R-26 and sulphur alkaliphilic Thiorhodospira sibirica ) is accelerated upon the addition of Mn 2+ jointly with bicarbonate (30–75 mM). The effect is not observed if Mn 2+ and HCO 3 − have been replaced by Mg 2+ and HCO 2 − , respectively. The dependence of the effect on bicarbonate concentration suggests that formation of Mn 2+ –bicarbonate complexes, Mn(HCO 3 ) + and/or Mn(HCO 3 ) 2 , is required for re-reduction of P 870 + with Mn 2+ . The results are considered as experimental evidence for a hypothesis on possible participation of Mn–bicarbonate complexes in the evolutionary origin of oxygenic photosynthesis in the Archean era.

Effects of Hydrogen Bonds on the Redox Potential and Electronic Structure of the Bacterial Primary Electron Donor†

Biochemistry ◽  
1998 ◽  
Vol 37 (34) ◽  
pp. 11812-11820 ◽  
Author(s):  
Anabella Ivancich ◽  
Katie Artz ◽  
JoAnn C. Williams ◽  
James P. Allen ◽  
Tony A. Mattioli
Keyword(s):  
Electronic Structure ◽  
Hydrogen Bonds ◽  
Redox Potential ◽  
Electron Donor ◽  
Primary Electron ◽  
Primary Electron Donor

The Effect of Mixtures of Xenobiotics and Primary Electron Donor on the Anaerobic Biotransformation of High Concentrations of Chlorinated Aliphatics

1992 ◽  
Vol 26 (1-2) ◽  
pp. 117-126 ◽  
Author(s):  
J. B. Hughes ◽  
G. F. Parkin
Keyword(s):  
Electron Donor ◽  
Mixed Effects ◽  
Primary Electron ◽  
Primary Electron Donor ◽  
Loading Rates ◽  
Chlorinated Aliphatics ◽  
Anaerobic Biotransformation ◽  
Transformation Rates ◽  
High Concentrations ◽  
Effect Of Feeding

Results are presented from experiments addressing the anaerobic biotransfoimation of high concentrations of three chlorinated aliphatics, dichloromethane (DCM), chloroform (CF), and 1,1,1-trichloroethane (TCA), when fed alone and in mixtures. Experiments were conducted to address the effect of feeding mixtures of these compounds on the transformation rates of individual components in the mixture, and to assess the effect of acetate loading rates on the extent of transformation of the chlorinated aliphatics. Feeding mixtures of chlorinated aliphatics caused decreased transformation of TCA, increased the transformation of DCM, and had mixed effects on CF transformation. The systems fed higher acetate loading rates demonstrated an increased ability to transform the chlorinated aliphatics.

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