title: Probing the carotenoid content of intact Cyclotella cells by resonance Raman spectroscopy.
abstract: In this study, we demonstrate the selective in vivo detection of diadinoxanthin (DD) and diatoxanthin (DT) in intact Cyclotella cells using resonance Raman spectroscopy. In these cells, we were able to assess both the content of DD and DT carotenoids relative to chlorophyll and their conformation. In addition, the sensitivity and selectivity of the technique allow us to discriminate between different pools of DD on a structural basis, and to follow their fate as a function of the illumination conditions. We report that the additional DD observed when cells are grown in high-light conditions adopts a more twisted conformation than the lower levels of DD present when the cells are grown in low-light (LL) conditions. Thus, we conclude that this pool of DD is more tightly bound to a protein-binding site, which must differ from the one occupied by the DD present in LL conditions.
authors.affiliation: Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan, 1081 HV, Amsterdam, The Netherlands, m.t.a.alexandre@vu.nl.
authors.forename: Maxime T A
authors.initials: MT
authors.lastname: Alexandre
authors.forename: Kathi
authors.initials: K
authors.lastname: Gundermann
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Pascal
authors.forename: Rienk
authors.initials: R
authors.lastname: van Grondelle
authors.forename: Claudia
authors.initials: C
authors.lastname: Büchel
authors.forename: Bruno
authors.initials: B
authors.lastname: Robert
mesh_terms: D001665:Binding Sites; D002338:Carotenoids / Q000032:analysis* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D017377:Diatoms / Q000254:growth & development / Q000378:metabolism*; D008027:Light; D013059:Spectrum Analysis, Raman / Q000379:methods*; D024341:Xanthophylls / Q000032:analysis / Q000378:metabolism
chemical_list: D024341:Xanthophylls; C025164:fucoxanthin; C033808:diadinoxanthin; D002338:Carotenoids; C103105:diatoxanthin