Origin of Absorption Changes Associated with Photoprotective Energy Dissipation in the Absence of Zeaxanthin

C. Ilioaia, M.P. Johnson, C.D.P. Duffy, A.A. Pascal, R. van Grondelle, B. Robert, A.V. Ruban

Research output: Contribution to JournalArticleAcademicpeer-review


To prevent photo-oxidative damage to the photosynthetic membrane in strong light, plants dissipate excess absorbed light energy as heat in a mechanism known as non-photochemical quenching (NPQ). NPQ is triggered by the transmembrane proton gradient (ΔpH), which causes the protonation of the photosystem II light-harvesting antenna (LHCII) and the PsbS protein, as well as the de-epoxidation of the xanthophyll violaxanthin to zeaxanthin. The combination of these factors brings about formation of dissipative pigment interactions that quench the excess energy. The formation of NPQ is associated with certain absorption changes that have been suggested to reflect a conformational change in LHCII brought about by its protonation. The light-minus-dark recovery absorption difference spectrum is characterized by a series of positive and negative bands, the best known of which is ΔA
Original languageEnglish
Pages (from-to)91-98
JournalJournal of Biological Chemistry
Issue number1
Publication statusPublished - 2011


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