Interactions of chloride and formate at the donor and the acceptor side of photosystem II.
Chloride is required for the maximum activity of the oxygen evolving complex (OEC) while formate inhibits the function of OEC. On the basis of the measurements of oxygen evolution rates and the S(2) state multiline EPR signal, an interaction between the action of chloride and formate at the donor side of PS II has been suggested. Moreover, the Fe(2)+Q-A EPR signals were measured to investigate a common binding site of both these anions at the PS II acceptor side. Other monovalent anions like bromide, nitrate etc. could influence the effects of formate to a small extent at the donor side of PS II, but not significantly at the acceptor side of PS II. The results presented in this paper clearly suggest a competitive binding of formate and chloride at the PS II acceptor side.
Jajoo
Anjana
A
School of Life Sciences, Devi Ahilya Vishwavidyalaya, Vigyan Bhawan, Khandwa Road, Indore 452 017, India. anjanajajoo@hotmail.com
Bharti
Sudhakar
S
Kawamori
Asako
A
D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D005561:Formates / Q000378:metabolism*; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism*; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D018724:Spinacia oleracea / Q000378:metabolism*
D002712:Chlorides; D005561:Formates; D045332:Photosystem II Protein Complex; C030544:formic acid; D010100:Oxygen