Spectroscopic Properties of Antenna Complexes from Purple Bacteria
This chapter describes the known factors which shape the electronic (and thus the functional) properties of light-harvesting (LH) complexes of purple bacteria. Although a variety of high- and low-resolution structures from LH complexes are now available, they do not provide, per se, a detailed picture of the electronic properties of the pigments in these complexes. However they constitute a framework which has helped, through the use of wide range of techniques, most often combining site-selection mutagenesis and advanced spectroscopies, to make progress in determining which parameters are important for the function of these proteins. Today, antenna proteins from purple photosynthetic bacteria are probably the best-understood photosynthetic LH proteins, and among the best-characterized membrane proteins in any biological field. However, there are still some discrepancies about the precise relationship between their structure and function. This chapter attempts to describe, as simply as possible, the physical mechanisms which are thought to underlie the tuning of the absorption properties of bacteriochlorophyll molecules in these proteins, as well as the results which are at the origin of the running arguments.
KeywordsChlorophyll Carbonyl Oligomer Polypeptide Arginine
Unable to display preview. Download preview PDF.
- Beekman LMP, Frese RN, Fowler GJS, Ortiz de Zarate I, Cogdell RJ, van Stokkum I, Hunter CN and van Grondelle R (1997a) Characterization of the light-harvesting antennas of photosynthetic purple bacteria by Stark spectroscopy. 2. LH2 complexes: Influence of the protein environment. J Phys Chem B 101: 7293–7301CrossRefGoogle Scholar
- Beekman LMP, Steffen M, van Stokkum I, Olsen JD, Hunter CN, Boxer SG and van Grondelle R (1997b) Characterization of the light-harvesting antennas of photosynthetic purple bacteria by Stark spectroscopy. 1. LH1 antenna complex and the B820 subunit from Rhodospirillum rubrum. J Phys Chem B 101: 7284–7292CrossRefGoogle Scholar
- Brunisholz RA, Bissig I, Niederer E, Suter F and Zuber H (1987) Structural studies on the light-harvesting polypeptides of Rp. acidophila. In: Biggins J (ed) Progress in Photosynthesis Research, Proceedings 7th International Congress of Photosynthesis, pp 13–16. Nijhoff, DordrechtGoogle Scholar
- Cogdell RJ, Hawthornthwaite AM, Evans MB, Ferguson LA, Kerfeld C, Thornber JP, Van Mourik F and van Grondelle R (1990) Isolation and characterization of an unusual antenna complex from the marine purple sulfur photosynthetic bacterium Chromatium purpuratum BN5500. Biochim Biophys Acta 1019: 239–244CrossRefGoogle Scholar
- Koolhaas MHC, Frese RN, Fowler GJS, Bibby TA, Georgakopoulou S, van der Zwan G, Hunter CN, and van Grondelle R (1998) Identification of the upper exciton component of the B850 bacteriochlorophylls of the LH2 antenna complex, using a B800-free mutant of Rhodobacter sphaeroides. Biochemistry 37: 4693–4698CrossRefGoogle Scholar
- Krikunova M, Kummrow A, Voigt B, Rini M, Lokstein H, Moskalenko, AA, Scheer H, Razjivin A and Leupold D (2002) Fluorescence of native and carotenoid-depleted LH2 from Chromatium minutissimum originating from simultaneous two-photon absorption in the spectral range of the presumed (optically ‘dark’) S1 state of carotenoids. FEBS Lett 530: 227–229CrossRefGoogle Scholar
- Matsushita M, Ketelaars M, Van Oijen AM, Köhler J, Aartsma TJ and Schmidt J (2001) Spectroscopy on the B850 band of individual light-harvesting 2 complexes of Rhodopseudomonas acidophila II. Exciton states of an elliptically deformed ring aggregate. Biophys J 80: 1604–1614PubMedCrossRefGoogle Scholar
- McLuskey K, Prince SM, Cogdell RJ and Isaacs NW (1999) Crystallization and preliminary X-ray crystallographic analysis of the B800–820 light-harvesting complex from Rhodopseudomonas acidophila strain 7050. Acta Cryst D55: 885–887Google Scholar
- Molisch H (1907) Die Purpurbakterien nach neuen Untersuchungen. Gustav Fisher, JenaGoogle Scholar
- Richter MF, Baier J, Prem T, Oellerich S, Francia F, Venturoli G, Oesterhelt D, Southall J, Cogdell RJ and Köhler J (2007) Symmetry matters for the electronic structure of core complexes from Rhodopseudomonas palustris and Rhodobacter sphaeroides PufX-. Proc Natl Acad Sci USA. 104: 6661–6665PubMedCrossRefGoogle Scholar
- Zuber H, and Brunisholz RA (1991) Structure and function of antenna polypeptides and chlorophyll-protein complexes: principles and variability. In Scheer H (ed) Chlorophylls, pp 627–703. CRC, Boca RatonGoogle Scholar