Pulsed EPR measurement of the distance between P680+. and Q(A)-. in photosystem II.
Out-of-phase electron spin echo envelope modulation (ESEEM) spectroscopy was used to determine the distance between the primary donor radical cation P680+. and the quinone acceptor radical anion Q(A)-. in iron-depleted photosystem II in membrane fragments from spinach that are deprived of the water oxidizing complex. Furthermore, a lower limit for the distance between the oxidized tyrosine residue Y(Z) of polypeptide D1 and Q(A)-. could be estimated by a comparison of data gathered from samples where the electron transfer from Y(Z) to P680+. is either intact or blocked by preillumination in the presence of NH2OH.
Zech
S G
SG
Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Germany.
Kurreck
J
J
Eckert
H J
HJ
Renger
G
G
Lubitz
W
W
Bittl
R
R
D016227:Benzoquinones; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005609:Free Radicals; D007501:Iron; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D045332:Photosystem II Protein Complex; D011487:Protein Conformation; D012680:Sensitivity and Specificity
D016227:Benzoquinones; D005609:Free Radicals; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; C004532:quinone; D007501:Iron