title: Light-dependent conformational change of neoxanthin in a siphonous green alga, Codium intricatum, revealed by Raman spectroscopy.
abstract: Siphonous green algae, a type of deep-sea green algae, appear olive drab and utilize blue-green light for photosynthesis. A siphonous green alga, Codium (C.) intricatum, was isolated from Okinawa prefecture in Japan, and a clonal algal culture in filamentous form was established. The major light-harvesting antenna was analogous to the trimeric LHCII found in higher plants, but the C. intricatum complex contained an unusual carbonyl carotenoid siphonaxanthin. Culture conditions were optimized to achieve high siphonaxanthin content in intact lyophilized filamentous bodies. Interestingly, the carotenoid composition was different when cultured under high irradiance: all-trans neoxanthin was accumulated in addition to the normal 9'-cis form in whole cell extract. Resonance Raman spectra of intact filamentous bodies, cultured under high- and low-light conditions, confirmed the accumulation of all-trans neoxanthin under high irradiance conditions. A plausible function of the presence of all-trans neoxanthin will be discussed in relation to the regulation against high light stress.
authors.affiliation: Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan.
authors.forename: Chiasa
authors.initials: C
authors.lastname: Uragami
authors.forename: Denise
authors.initials: D
authors.lastname: Galzerano
authors.forename: Andrew
authors.initials: A
authors.lastname: Gall
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shigematsu
authors.forename: Maïwen
authors.initials: M
authors.lastname: Meisterhans
authors.forename: Naohiro
authors.initials: N
authors.lastname: Oka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Iha
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Fujii
authors.forename: Bruno
authors.initials: B
authors.lastname: Robert
authors.forename: Hideki
authors.initials: H
authors.lastname: Hashimoto
mesh_terms: D000460:Chlorophyta / Q000737:chemistry* / Q000378:metabolism*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D024341:Xanthophylls / Q000737:chemistry / Q000378:metabolism*
chemical_list: D024341:Xanthophylls; C003314:siphonaxanthin; C011947:neoxanthin