title: Resonance Raman studies on the structure of bacteriochlorophyll c in chlorosomes from Chloroflexus aurantiacus.
abstract: Resonance Raman spectra of chlorosomes isolated from the thermophilic green photosynthetic bacterium Chloroflexus aurantiacus have been obtained with several excitation wavelengths from 441.6 to 514.5 nm. Resonance Raman spectra of bacteriochlorophyll (BChl) c isolated from C. aurantiacus cells have also been observed. The C=C stretching frequencies of BChl c in the chlorosomes were found to be at 1,556 (strong) and 1,544 (shoulder) cm-1, which correspond to those expected for the 5-coordinated BChl c. The C-9 carbonyl resonance Raman frequency was found at 1,642 cm-1, indicating that this group is either hydrogen-bonded to an Mg-coordinated hydroxyl group or coordinated to the Mg ion.
authors.affiliation: Department of Molecular Chemistry and Engineering, Faculty of Engineering, Tohoku University, Miyagi.
authors.forename: T
authors.initials: T
authors.lastname: Nozawa
authors.forename: T
authors.initials: T
authors.lastname: Noguchi
authors.forename: M
authors.initials: M
authors.lastname: Tasumi
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D010776:Photobacterium / Q000032:analysis*; D013059:Spectrum Analysis, Raman
chemical_list: D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; D006878:Hydroxides; C002084:bacteriochlorophyll c; C031356:hydroxide ion; D008274:Magnesium