Redox interaction of Mn-bicarbonate complexes with reaction centres of purple bacteria.
Philos Trans R Soc Lond B Biol Sci
; 363(1494): 1245-51; discussion 1251, 2008 Mar 27.
Article
in En
| MEDLINE
| ID: mdl-17971330
ABSTRACT
It is found that dark reduction of photooxidized primary electron donor P870+ 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 Mn2+ jointly with bicarbonate (30-75 mM). The effect is not observed if Mn2+ and HCO3(-) have been replaced by Mg2+ and HCO2(-), respectively. The dependence of the effect on bicarbonate concentration suggests that formation of Mn2+-bicarbonate complexes, Mn(HCO3)+ and/or Mn(HCO3)2, is required for re-reduction of P870+ with Mn2+. 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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bicarbonates
/
Rhodobacter sphaeroides
/
Photosynthetic Reaction Center Complex Proteins
/
Manganese
Language:
En
Journal:
Philos Trans R Soc Lond B Biol Sci
Year:
2008
Document type:
Article
Affiliation country:
RUSSIA