Conformation of bacteriochlorophyll molecules in photosynthetic proteins from purple bacteria.
Détails
ID Serval
serval:BIB_690525E87D4D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Conformation of bacteriochlorophyll molecules in photosynthetic proteins from purple bacteria.
Périodique
Biochemistry
ISSN
0006-2960 (Print)
ISSN-L
0006-2960
Statut éditorial
Publié
Date de publication
1999
Volume
38
Numéro
34
Pages
11115-11121
Langue
anglais
Résumé
Fourier transform near-infrared resonance Raman spectroscopy can be used to obtain information on the bacteriochlorophyll a (BChl a) molecules responsible for the redmost absorption band in photosynthetic complexes from purple bacteria. This technique is able to distinguish distortions of the bacteriochlorin macrocycle as small as 0.02 A, and a systematic analysis of those vibrational modes sensitive to BChl a macrocycle conformational changes was recently published [Näveke et al. (1997) J. Raman Spectrosc. 28, 599-604]. The conformation of the two BChl a molecules constituting the primary electron donor in bacterial reaction centers, and of the 850 and 880 nm-absorbing BChl a molecules in the light-harvesting LH2 and LH1 proteins, has been investigated using this technique. From this study it can be concluded that both BChl a molecules of the primary electron donor in the photochemical reaction center are in a conformation close to the relaxed conformation observed for pentacoordinate BChl a in diethyl ether. In contrast, the BChl a molecules responsible for the long-wavelength absorption transition in both LH1 and LH2 antenna complexes are considerably distorted, and furthermore there are noticeable differences between the conformations of the BChl molecules bound to the alpha- and beta-apoproteins. The molecular conformations of the pigments are very similar in all the antenna complexes investigated.
Mots-clé
Bacterial Proteins, Bacteriochlorophylls/chemistry, Light-Harvesting Protein Complexes, Photosynthetic Reaction Center Complex Proteins/chemistry, Protein Conformation, Purple Membrane/chemistry, Rhodobacter sphaeroides/chemistry, Rhodopseudomonas/chemistry, Rhodospirillum/chemistry, Rhodospirillum rubrum/chemistry, Spectroscopy, Fourier Transform Infrared
Pubmed
Web of science
Création de la notice
28/11/2011 16:08
Dernière modification de la notice
20/08/2019 15:24