The Native Reaction Centre of Photosystem II: A New Paradigm for P680
Joseph L. Hughes A , Barry J. Prince A , Sindra Peterson Årsköld A D , Paul J. Smith B , Ron J. Pace B , Hans Riesen C and Elmars Krausz A EA Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia.
B Faculties Chemistry, Australian National University, Canberra ACT 0200, Australia.
C School of Physical, Environmental and Mathematical Sciences, University of New South Wales, ADFA, Canberra ACT 2600, Australia.
D Department of Biochemistry, Lund University, 22100 Lund, Sweden.
E Corresponding author. Email: krausz@rsc.anu.edu.au
Australian Journal of Chemistry 57(12) 1179-1183 https://doi.org/10.1071/CH04140
Submitted: 1 June 2004 Accepted: 20 September 2004 Published: 8 December 2004
Abstract
Low-temperature spectra of fully active (oxygen-evolving) Photosystem II (PSII) cores prepared from spinach exhibit well developed structure. Spectra of isolated sub-fragments of PSII cores establish that the native reaction centre is better structured and red-shifted compared to the isolated reaction centre. Laser illumination of PSII cores leads to efficient and deep spectral hole-burning. Measurements of homogeneous hole-widths establish excited-state lifetimes in the 40–300 ps range. The high hole-burning efficiency is attributed to charge separation of P680 in native PSII that follows reaction-centre excitation via ‘slow transfer’ states in the inner light-harvesting assemblies CP43 and CP47. The ‘slow transfer’ state in CP47 and that in CP43 can be distinguished in the hole-burning action spectrum and high-resolution hole-burning spectra. An important observation is that 685–700 nm illumination gives rise to efficient P680 charge separation, as established by QA− formation. This leads to a new paradigm for P680. The charge-separating state has surprisingly weak absorption and extends to 700 nm.
[1]
[2]
P. J. Smith,
S. Peterson,
V. M. Masters,
T. Wydrzynski,
S. Styring,
E. Krausz,
R. J. Pace,
Biochemistry 2002, 41, 1981.
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
| Crossref | GoogleScholarGoogle Scholar |
