title: Thermostability of Rhodopseudomonas viridis and Rhodospirillum rubrum chromatophores reflecting physiological conditions.
abstract: Relationships between growth conditions and thermostability were examined for photosynthetic inner membranes (chromatophores) from Rhodopseudomonas viridis and Rhodospirillum rubrum of which morphology, lipid composition, and protein/lipid rate are rather mutually different. Signals observed by differential scanning calorimetry of the chromatophores were correlated with thermal state transitions of the membrane components by reference to temperature dependencies of circular dichroism and absorption spectra of the purified supramolecule comprising a photoreaction center and surrounding light-harvesting pigment-protein complexes that are the prominent proteins in both membranes. The differential scanning calorimetry curves of those chromatophores exhibited different dependencies on growth stages and environmental temperatures. The obtained result appeared to reflect the differences in the protein/lipid rate and protein-lipid specificity between the two chromatophores.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central-6, 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan. odahara-takayuki@aist.go.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Odahara
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ishii
authors.forename: Ayako
authors.initials: A
authors.lastname: Ooishi
authors.forename: Shinya
authors.initials: S
authors.lastname: Honda
authors.forename: Hatsuho
authors.initials: H
authors.lastname: Uedaira
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hara
authors.forename: Jun
authors.initials: J
authors.lastname: Miyake
mesh_terms: D020130:Bacterial Chromatophores / Q000737:chemistry* / Q000648:ultrastructure; D002152:Calorimetry, Differential Scanning; D002793:Cholic Acids / Q000737:chemistry; D002942:Circular Dichroism; D008854:Microscopy, Electron; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism; D055550:Protein Stability; D058767:Protein Unfolding; D012241:Rhodopseudomonas / Q000737:chemistry* / Q000254:growth & development; D012247:Rhodospirillum rubrum / Q000737:chemistry* / Q000254:growth & development; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D002793:Cholic Acids; D045322:Photosynthetic Reaction Center Complex Proteins; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate