Xanthophyll pigments in light-harvesting complex II in monomolecular layers: localisation, energy transfer and orientation

摘要: Monomolecular layers of the largest light-harvesting pigment-protein complex Photosystem II (LHCII) were formed at argon-water interface. The molecular area LHCII monomer in monomolecular determined from isotherms compression is found to be close 14 nm2, which corresponds well dimensions protein evaluated on basis crystallographic studies. Monolayers deposited a glass support by means Langmuir-Blodgett technique and subjected spectroscopic studies: electronic absorption spectrophotometry spectrofluorometry. fluorescence excitation spectra chlorophyll monolayers analysed using gaussian deconvolution. Comparison enabled calculation rate energy transfer system. Excitation was transferred b with 97% efficiency, neoxanthin 85%, lutein 62% violaxanthin least 54% efficiency. analysis position 0-0 band xanthophylls revealed that located same environment as but different than violaxanthin. LHCII, recorded light beam polarised two orthogonal directions, determination mean orientation angle accessory xanthophyll pigments respect plane sample. this study (approx. 51 degrees ) data. Neoxanthin adopt similar lutein. transition dipole moment form 71 axis spanning polar regions protein, perpendicular monolayer, suggesting planar pigment thylakoid membrane. These experimentally orientations are discussed terms importance peripheral supramolecular organisation operation cycle within