Abstract
Heat-stable photosynthetic light-harvesting membrane protein (LH2) that has a cylindrical structure of 7 nm diameter was introduced into the inorganic nanoporous material that has honeycomb-like hexagonal cylindrical interior channels with a diameter of 7.9 nm. LH2 was purified by the detergent treatment of the membranes of a thermophilic purple photosynthetic bacterium Thermochromatium tepidum by HPLC column chromatography. The measurement of N2 adsorption indicated that most of LH2 molecules were adsorbed inside the nano-pores. Absorption spectrum of LH2 inside nono-pores was similar to free LH2 except for a slight red shift (3 nm) of B850 band. The energy transfer from B800 to B850 was very rapid. The ring structure as well as the antenna function of LH2, therefore, seems to be well maintained inside nano-pores. Fluorescence decay of the adsorbed LH2 was remarkably faster (27 ps). Fluctuation of LH2 structure inside nano-pores will be discussed.
