Light control over the size of an antenna unit building block as an efficient strategy for light harvesting in photosynthesis.
It was shown that an increase in the bacteriochlorophyll (BChl) c antenna size observed upon lowering growth light intensities led to enhancement of the hyperchromism of the BChl c Q(y) absorption band of the green photosynthetic bacterium Chloroflexus aurantiacus. With femtosecond difference absorption spectroscopy, it was shown that the amplitude of bleaching of the oligomeric BChl c Q(y) band (as compared to that for monomeric BChl a) increased with increasing BChl c content in chlorosomes. This BChl c bleaching amplitude was about doubled as the chlorosomal antenna size was about trebled. Both sets of findings clearly show that a unit BChl c aggregate in the chlorosomal antenna is variable in size and governed by the grow light intensity, thus ensuring the high efficiency of energy transfer within the BChl c antenna regardless of its size.
Yakovlev
A G
AG
A.N. Belozersky Institute of Physico-Chemical Biology, Bldg. 'A', Moscow State University, 119899, Moscow, Russia.
Taisova
A S
AS
Fetisova
Z G
ZG
D001426:Bacterial Proteins / Q000528:radiation effects; D001429:Bacteriochlorophylls / Q000528:radiation effects; D019414:Chlorobi / Q000378:metabolism / Q000528:radiation effects*; D045342:Light-Harvesting Protein Complexes; D010788:Photosynthesis / Q000528:radiation effects*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000528:radiation effects*
D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; C002084:bacteriochlorophyll c