光合成アンテナ複合体の単一分子分光

抄録

Due to thermal motion protein is always changing its three-dimensional structure. Characteristics of individual structures are usually hidden under temporal and ensemble averaging. A direct method to study individuals is to freeze thermal motion at low temperature and perform spectroscopy on individual proteins. This method has been applied to pigment-protein complex called light-harvesting 2 (LH2) complex from photosynthetic bacteria. In the fluorescence excitation spectrum of individual LH2 complexes taken at 1.5 K narrow peaks around 800 nm represent excitation of individual bacteriochlorophyll (BChl) a molecules while broad spectral feature around 860 nm reflects delocalized nature of excitation involving BChl a molecules arranged on a circle.