Runa Sakamoto, Ibuki Y Takahashi, Koji Kato, Yoshiki Nakajima, Jian-Ren Shen, Ryo Nagao
{"title":"Purification and pigment analysis of diadinoxanthin-binding PSI-LHCI supercomplexes from <i>Euglena gracilis</i> strain Z.","authors":"Runa Sakamoto, Ibuki Y Takahashi, Koji Kato, Yoshiki Nakajima, Jian-Ren Shen, Ryo Nagao","doi":"10.17912/micropub.biology.001678","DOIUrl":null,"url":null,"abstract":"<p><p><i>Euglena gracilis</i> exhibits a unique pigment profile distinct from land plants and green algae. In this study, we purified photosystem I supercomplexes containing light-harvesting complexes (PSI-LHCI) from <i>E. gracilis</i> strain Z and analyzed their biochemical and spectroscopic properties. The PSI-LHCI contained diadinoxanthin while lacking lutein and violaxanthin, which are characteristic of green-lineage organisms. The absorption and 77-K fluorescence spectra of <i>Euglena</i> PSI-LHCI showed the Qy peak of chlorophyll <i>a</i> at 675 nm and emission at 732 nm, respectively, comparable to land plant PSI-LHCI. These findings suggest conservation of long-wavelength chlorophylls despite distinct pigment-binding characteristics, shedding light on light-harvesting adaptations in secondary green algae.</p>","PeriodicalId":74192,"journal":{"name":"microPublication biology","volume":"2025 ","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12364551/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"microPublication biology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.17912/micropub.biology.001678","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/1 0:00:00","PubModel":"eCollection","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Euglena gracilis exhibits a unique pigment profile distinct from land plants and green algae. In this study, we purified photosystem I supercomplexes containing light-harvesting complexes (PSI-LHCI) from E. gracilis strain Z and analyzed their biochemical and spectroscopic properties. The PSI-LHCI contained diadinoxanthin while lacking lutein and violaxanthin, which are characteristic of green-lineage organisms. The absorption and 77-K fluorescence spectra of Euglena PSI-LHCI showed the Qy peak of chlorophyll a at 675 nm and emission at 732 nm, respectively, comparable to land plant PSI-LHCI. These findings suggest conservation of long-wavelength chlorophylls despite distinct pigment-binding characteristics, shedding light on light-harvesting adaptations in secondary green algae.