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Zeaxanthin radical cation formation in minor light-harvesting complexes of higher plant antenna

Avenson, T. J.; Ahn, T. K.; Zigmantas, Donatas LU ; Niyogi, K. K.; Li, Z.; Ballottari, M.; Bassi, R. and Fleming, G. R. (2008) In Journal of Biological Chemistry 283(6). p.3550-3558
Abstract
Previous work on intact thylakoid membranes showed that transient formation of a zeaxanthin radical cation was correlated with regulation of photosynthetic light-harvesting via energy-dependent quenching. A molecular mechanism for such quenching was proposed to involve charge transfer within a chlorophyll-zeaxanthin heterodimer. Using near infrared (880 - 1100 nm) transient absorption spectroscopy, we demonstrate that carotenoid (mainly zeaxanthin) radical cation generation occurs solely in isolated minor light-harvesting complexes that bind zeaxanthin, consistent with the engagement of charge transfer quenching therein. We estimated that less than 0.5% of the isolated minor complexes undergo charge transfer quenching in vitro, whereas the... (More)
Previous work on intact thylakoid membranes showed that transient formation of a zeaxanthin radical cation was correlated with regulation of photosynthetic light-harvesting via energy-dependent quenching. A molecular mechanism for such quenching was proposed to involve charge transfer within a chlorophyll-zeaxanthin heterodimer. Using near infrared (880 - 1100 nm) transient absorption spectroscopy, we demonstrate that carotenoid (mainly zeaxanthin) radical cation generation occurs solely in isolated minor light-harvesting complexes that bind zeaxanthin, consistent with the engagement of charge transfer quenching therein. We estimated that less than 0.5% of the isolated minor complexes undergo charge transfer quenching in vitro, whereas the fraction of minor complexes estimated to be engaged in charge transfer quenching in isolated thylakoids was more than 80 times higher. We conclude that minor complexes which bind zeaxanthin are sites of charge transfer quenching in vivo and that they can assume Non-quenching and Quenching conformations, the equilibrium LHC(N) reversible arrow LHC(Q) of which is modulated by the transthylakoid pH gradient, the PsbS protein, and protein-protein interactions. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
xanthophyll cycle, chlorophyll fluorescence, resolved fluorescence analysis, photosystem-ii, energy-dissipation, excited-states, in-vivo, protein cp26, oxygenic photosynthesis, green plants
in
Journal of Biological Chemistry
volume
283
issue
6
pages
3550 - 3558
publisher
ASBMB
external identifiers
  • scopus:41249094699
ISSN
1083-351X
DOI
10.1074/jbc.M705645200
language
English
LU publication?
no
id
ee2e5b7c-ad72-4087-8abe-c43b34c40388 (old id 1432904)
date added to LUP
2009-07-02 14:57:25
date last changed
2017-11-19 04:19:21
@article{ee2e5b7c-ad72-4087-8abe-c43b34c40388,
  abstract     = {Previous work on intact thylakoid membranes showed that transient formation of a zeaxanthin radical cation was correlated with regulation of photosynthetic light-harvesting via energy-dependent quenching. A molecular mechanism for such quenching was proposed to involve charge transfer within a chlorophyll-zeaxanthin heterodimer. Using near infrared (880 - 1100 nm) transient absorption spectroscopy, we demonstrate that carotenoid (mainly zeaxanthin) radical cation generation occurs solely in isolated minor light-harvesting complexes that bind zeaxanthin, consistent with the engagement of charge transfer quenching therein. We estimated that less than 0.5% of the isolated minor complexes undergo charge transfer quenching in vitro, whereas the fraction of minor complexes estimated to be engaged in charge transfer quenching in isolated thylakoids was more than 80 times higher. We conclude that minor complexes which bind zeaxanthin are sites of charge transfer quenching in vivo and that they can assume Non-quenching and Quenching conformations, the equilibrium LHC(N) reversible arrow LHC(Q) of which is modulated by the transthylakoid pH gradient, the PsbS protein, and protein-protein interactions.},
  author       = {Avenson, T. J. and Ahn, T. K. and Zigmantas, Donatas and Niyogi, K. K. and Li, Z. and Ballottari, M. and Bassi, R. and Fleming, G. R.},
  issn         = {1083-351X},
  keyword      = {xanthophyll cycle,chlorophyll fluorescence,resolved fluorescence analysis,photosystem-ii,energy-dissipation,excited-states,in-vivo,protein cp26,oxygenic photosynthesis,green plants},
  language     = {eng},
  number       = {6},
  pages        = {3550--3558},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {Zeaxanthin radical cation formation in minor light-harvesting complexes of higher plant antenna},
  url          = {http://dx.doi.org/10.1074/jbc.M705645200},
  volume       = {283},
  year         = {2008},
}