M. Wentworth et al., Chlorophyll fluorescence quenching in isolated light harvesting complexes induced by zeaxanthin, FEBS LETTER, 471(1), 2000, pp. 71-74
Non-photochemical quenching of chlorophyll fluorescence in plants occurs in
the light harvesting antenna of photosystem II and is regulated by the xan
thophyll cycle. A nem in vitro model for this process has been developed. P
urified light harvesting complexes above the detergent critical micelle con
centration have a stable high fluorescence yield but a rapidly inducible fl
uorescence quenching occurs upon addition of zeaxanthin. Violaxanthin was w
ithout effect, lutein and antheraxanthin induced a marginal response, where
as the violaxanthin analogue, auroxanthin, induced strong quenching. Quench
ing was not caused by aggregation of the complexes but was accompanied by a
spectral broadening and red shift, indicating a zeaxanthin-dependent alter
ation in the chlorophyll environment. (C) 2000 Federation of European Bioch
emical Societies.