摘要
The effect of varying pH on the photosystem II (PSII) membrane was studied using absorption and steady state fluorescence spectroscopy, and using a variable fluorescence technique. pH variations induced significant changes in the chlorophyll states of the PSII membrane, but no effect was seen on the chlorophyll fluorescence parameter F ′ v/ F ′ m. For acidic pH conditions, protein structures of the PSII membrane were slightly altered, whilst at alkaline pH levels, large changes in the protein structure of the PSII membrane were detected. The results indicate that the microenvironment around Cys in the PSII membrane is very susceptible to alkaline pH conditions, and that in the acid (4≤pH<7) and alkaline (9≥pH>7) regions, pH variation has no effect on the protein structures of the PSII reaction center (RC).
The effect of varying pH on the photosystem II (PSII) membrane was studied using absorption and steady state fluorescence spectroscopy, and using a variable fluorescence technique. pH variations induced significant changes in the chlorophyll states of the PSII membrane, but no effect was seen on the chlorophyll fluorescence parameter F ′ v/ F ′ m. For acidic pH conditions, protein structures of the PSII membrane were slightly altered, whilst at alkaline pH levels, large changes in the protein structure of the PSII membrane were detected. The results indicate that the microenvironment around Cys in the PSII membrane is very susceptible to alkaline pH conditions, and that in the acid (4≤pH<7) and alkaline (9≥pH>7) regions, pH variation has no effect on the protein structures of the PSII reaction center (RC).
基金
Supported by the State Key Basic Research and Developm ent Plan (No. G19980 10 10 0 ) and the National Natural Science Foundation of China (No.39890 390 )
