Isolation And Characterization Of Photosynthetic Membrane Protein Complexes From Ulva Lactuca

Marine algae photosynthetic membrane protein structure and function showed that the pigment-protein complexes of green algae are diversity, this is to adapt to the marine living enviro nment. It is also found that marine algae have special characteristics in the structure of photosynthetic membrane protein complexes, energy transfer and spectras. However the compositions of pigments and fluorescence characteristics have not been well investigated. These foundational issues were studied in this paper.First of all, thylakoid membrane from Ulva by was successfully extracted by using differential centrifugation, the light-harvesting system of Ulva was larger. LHCII from Ulva was successfully extracted by using a continuous freeze-thaw sucrose gradient centrifugation for the first time. The extracted protein showed only a 27 kDa band on SDS-PAGE. Compared with spinach LHCII, the lack of 25 kDa bands indicated that two subtypes might be difference. Ulva LHCII and spinach LHCII in the pigment composition were roughly the same, but Ulva LHCII had a pigment Chl a'which was not found in spinach LHCII. Further, through the separation of sucrose gradient centrifugation, Ulva LHCII and spinach LHCII were both mainly in trimer. Ulva LHCII and spinach LHCII differed more in the blue zone in CD spectra, suggesting that Ulva carotenoid molecules and protein binding conformation are different from the higher plants.There was also obvious difference between Ulva and spinach thylakoid membrane in thermal stability. The Tm of Ulva thylakoid membrane's was 5°C higher than that of the spinach thylakoid membrane. In the spinach thylakoid membrane, the temperature firstly affects the energy transfer in membrane protein, then the interaction between pigment and pigment itself. Thirdly, hydrothermal synthesis of nano-ZnO seeds in the FTO glass generated uniform distribution with particle size 20~40 nm; LB Film instrument was used to transfer thylakoid membranes to nano-ZnO glass. Thylakoid membrane and the formation of nano-ZnO adsorption was Z-type LB films. thylakoid membranes on nano-ZnO glass conductive film has generated a good electrical conductivity propertie, and with the increase in the number of LB film current is increasing, with the spinach thylakoid membrane made of open-circuit voltage and the conductive film short-circuit current than the same layers Ulva thylakoid conductive film small.