FLUORESCENCE SPECTRAL FLUCTUATIONS OF SINGLE LH2 COMPLEXES FROM RHODOPSEUDOMONAS ACIDOPHILA STRAIN 10050

摘要

Since a high-resolution structure of the peripheral light-harvesting complex (LH2) of the photosynthetic bacterium Rhodopseudomonas (Rps.) addophila has become available (McDermott et al 1995, Papiz et al 2003), the molecule has played a key role in aiding our current understanding of photosynthetic light-harvesting (Cogdell et al 1996, Hu et al 2002, Robert et al 2003, Sundstrom et al 1999). From the detailed study of the spectroscopic and energy transfer properties of LH2, a consistent physical picture of the complex has emerged (Alden et al 1997, Hu et al 1997, Sauer et al 1996, Scholes & Fleming 2000, Wu et al 1997). Based on room and low temperature single molecule experiments it has been proposed that the LH2 ring can deviate from the ideallycircular structure (Bopp et al 1999, Ketelaars et al 2001, Matsushita et al 2001, van Oijen et al 1999). In general, the observed variation of the spectral and functional properties of LH2 suggests that the complex can undergo a variety of deformations.It is reasonable to assume that such dynamic structural alterations also underlie the pattern of the static disorder of pigment site energies that play a key role in understanding of the spectroscopic and energy transfer properties of LH2.