title: Single supramolecule spectroscopy of natural and alkaline-treated chlorosomes from green sulfur photosynthetic bacteria.
abstract: Fluorescence emission properties of intact and alkaline-treated chlorosomes containing bacteriochlorophyll(BChl)-c, d, and e, which were isolated from four species of green sulfur photosynthetic bacteria, were successfully studied at the single-unit level using a total internal reflection fluorescence microscope. Single intact chlorosomes containing BChl-c from Chlorobium (Chl.) tepidum exhibited heterogeneous emission bands of BChl-c self-aggregates. In contrast, fluorescence spectra of chlorosomal BChl self-aggregates in single intact chlorosomes from the other three Chlorobium species were less heterogeneous than those from Chi. tepidum. Removal of energy-accepting BChl-a/protein complexes called baseplates from the intact chlorosomes by treatments with alkaline media hardly changed spectral shapes of BChl aggregates and their peak distributions at the single-chlorosome level. The similarity of spectral properties at the single-unit level between intact and alkaline-treated chlorosomes of four Chlorobium species clearly indicated that the removal of base-plates from intact chlorosomes by the alkaline-treatment did not affect BChl self-aggregates inside single chlorosomes.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Saga
authors.forename: Tetsuichi
authors.initials: T
authors.lastname: Wazawa
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ishii
authors.forename: Toshio
authors.initials: T
authors.lastname: Yanagida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tamiaki
mesh_terms: D000468:Alkalies; D041883:Chlorobium / Q000737:chemistry* / Q000235:genetics; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D046912:Multiprotein Complexes; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology; D010316:Particle Size; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
chemical_list: D000468:Alkalies; D045342:Light-Harvesting Protein Complexes; D046912:Multiprotein Complexes