Polarization Measurements on Single Pigment-Protein Complexes

✍ Scribed by Carsten Tietz; Uwe Gerken; Fedor Jelezko; Jörg Wrachtrup

• Book ID: 101291297
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 213 KB
• Volume: 1
• Category: Article
• ISSN: 1438-5163
• DOI: 10.1002/(sici)1438-5171(200004)1:1<67::aid-simo67>3.0.co;2-4

✦ Synopsis

Individual antenna complexes from different photosynthetic units have been investigated by single molecule spectroscopy. In such energy transfer systems the polarization of the fluorescence emission gives valuable information about the nature of the emitting state, which is not readily available with other methods like fluorescence excitation or emission spectroscopy. The peripheral antenna light harvesting complex from purple bacterium Rhodopseudomonas Acidophila shows predominantly linear polarized fluorescence emission at low temperature, whereas at room temperature the fluorescence is randomly polarized. This is attributed to the fact, that at low temperature in the fluorescence emitting state the excitation energy is localized mainly on 4-5 chromophores. Analysis of the fluorescence emission of single peripheral antenna complexes of green plants indicate that for trimers of this species more than one Chlorophyll is responsible for the final fluorescence emission, which points towards a weak intermonomer coupling in the complex.