Picosecond spectroscopy of the isolated reaction centers from the photosystems of oxygenic photosynthesis—ten years (1987–1997) of fun

Abstract

Mike Wasielewski's pioneering work on Photosystem II photochemistry has an important place in the history of photosynthesis; we are proud to have been associated with him in making those first measurements. Here, we present our association and publications with him, and provide some of the history behind this research.

From Förster resonance energy transfer to coherent resonance energy transfer and back

“…Most researchers define trapping of excitation energy only up to the time that primary charge separation takes place. In our opinion, and those gleaned from the majority of papers, the primary charge separation involving reaction center chlorophylls and pheophytins, is in the range of a few ps (0.3 ps-8ps; see a historical report 115 ), but the time of the excitation migration to the unit where charge separation occurs is much longer, e.g., 20-50 ps. Thus, it is generally believed that the system is limited by "transfer-to-the-trap" [116][117] .…”

A Significant Loss in Photosynthetic Activity Associated with the Yellow Vine Syndrome of Cranberry

“…Chlorophyll fluorescence analysis. The kinetics of the electron transfer steps in photosynthetic reaction centers has been thoroughly investigated over the complete timescale of femtoseconds to many seconds (Brudvig, 2008;Govindjee and Seibert, 2010;Rappaport and Diner, 2008;Renger and Holzwarth, 2005;Seibert and Wasielewski, 2003;van Grondelle and Gobets, 2004). The early electron transfer occurring in PSII revealed by ultrafast spectroscopy can be divided into several steps: 1) absorption of light quanta by antenna to form excited states of pigments; 2) trapping of excitation energy by the primary electron donor P 680 in the reaction center on the picosecond time scale; 3) primary charge separation from the singlet excited state of P 680 to the primary acceptor Pheo in %3 to 20 ps; 4) stabilization of the separated charges from the radical pair P 680 + Pheoon the acceptor side by electron transfer to Q A in %200 ps and to Q B on the hundreds-of-ms time scale; and 5) on the donor side, an electron is supplied to reduce P 680 + from water through a tyrosine residue (Y Z ) and Mn 4 Ca cluster involving a S-state oxygen evolution cycle on the ns-ms time scale (Brudvig, 2008;Debus, 1992;Diner and Babcock, 1996;Kok and Radmer, 1976;Rutherford et al, 1992;Tommos and Babcock, 2000).…”

Biology and biotechnological applications of microalgae and photosynthetic prokaryotes: part 2

“…Accurate measurements were difficult at the time due to the extreme light-, oxygen-, and temperature-sensitivity of the PS II chlorophyllprotein complexes, but we did not 'give-up'. For summary of this work, see Seibert and Wasielewski (2005) and Govindjee and Seibert (2010). In addition, in 1990, Govindjee and I collaborated, in work done at the University of Illinois at Urbana-Champaign, UIUC, on fluorescence lifetime distributions in isolated PS II RCPs .…”