Thr role of phosphatidylglycerol (PG) in photosystem Ⅱ (PSⅡ) was investigated through enzymatic approach. It was shown that the function sites in the PSⅡ complex for PG might be near the oxygen evolution complex of PSⅡ. Depletion of PG caused the inhibition of oxygen evolving activity in PSⅡ, and also gave rise to the changes in the protein secondary structures of PSⅡ, that is , the decreases in the α-helical and turn conformations accompanied by the increases in the β-sheet structures. In addition, the conformation and microenvironment of tyrosyl residue of proteins were markedly affected.

Key words: PROTEIN