Biochemistry (Moscow)

, Volume 69, Issue 11, pp 1299–1304

Interaction of pigment—protein complexes within aggregates stimulates dissipation of excess energy

Authors

  • N. V. Karapetyan
    • Bach Institute of BiochemistryRussian Academy of Sciences
Review

DOI: 10.1007/s10541-005-0075-6

Cite this article as:
Karapetyan, N.V. Biochemistry (Moscow) (2004) 69: 1299. doi:10.1007/s10541-005-0075-6

Abstract

Pigment—protein complexes in photosynthetic membranes exist mainly as aggregates that are functionally active as monomers but more stable due to their ability to dissipate excess energy. Dissipation of energy in the photosystem I (PSI) trimers of cyanobacteria takes place with a contribution of the long-wavelength chlorophylls whose excited state is quenched by cation radical of P700 or P700 in its triplet state. If P700 in one of the monomer complexes within a PSI trimer is oxidized, energy migration from antenna of other monomer complexes to cation radical of P700 via peripherally localized long-wave-length chlorophylls results in energy dissipation, thus protecting PSI complex of cyanobacteria against photodestruction. It is suggested that dissipation of excess absorbed energy in aggregates of the light-harvesting complex LHCII of higher plants takes place with a contribution of peripherally located chlorophylls and carotenoids.

Key words

antenna chlorophyllP700energy dissipationlight-harvesting complex LHCIIphotosystem I trimer

Abbreviations

C708 (C740, etc.)

chlorophylls with absorption maximum at 708 nm (740 nm, etc.)

LHCII, LHCI

light harvesting complexes of PSII and PSI, respectively

F760 (F730, etc.)

fluorescence band with emission maximum at 760 nm (730 nm, etc.)

P700

primary electron donor of PSI

PSI, PSII

photosystems I and II, respectively

Copyright information

© MAIK “Nauka/Interperiodica” 2004