Tf. Prisner et al., MEASUREMENT OF THE G-TENSOR OF THE P700-DOT SIGNAL FROM DEUTERATED CYANOBACTERIAL PHOTOSYSTEM-I PARTICLES(CENTER), Proceedings of the National Academy of Sciences of the United Statesof America, 90(20), 1993, pp. 9485-9488
We report high-field continuous wave EPR spectra of P700+. in preparat
ions obtained from deuterated cyanobacteria (Synechococcus lividus). M
easurements were performed with photosystem I (PS-I) preparations, who
le cells from cyanobacteria grown in (H2O)-H-2, and photosystem II (PS
-H) preparations, as well as with protonated PS-I preparations. Becaus
e of the significantly improved resolution of our 140-GHz spectrometer
(as compared with X- or Q-band EPR) the principal values of the g-ten
sor of the primary donor P700+. could be resolved and measured with hi
gh accuracy as g11 = 2.00304, g22 = 2.00262, and g33 = 2.00232. Other
signals arising from Mn2+ and a dark signal from PS-IL at g almost-equ
al-to 2.00266 are distinguished from the P700+. g-tensor powder patter
n. The measured g values are compared with those of several bacterial
reaction center donors.