title: Studying the spatial organization of membrane proteins by means of tritium stratigraphy: bacteriorhodopsin in purple membrane.
abstract: The topography of bacteriorhodopsin (bR) in situ was earlier studied by using the tritium bombardment approach [Eur. J. Biochem. 178 (1988) 123]. Now, having the X-ray crystallography data of bR at atom resolution [Proc. Natl. Acad. Sci. 95 (1998) 11673], we estimated the influence of membrane environment (lipid and protein) on tritium incorporation into amino acid residues forming transmembrane helices. We have determined the tritium flux attenuation coefficients for residues 10-29 of helix A. They turned out to be low (0.04+/-0.02 A(-1)) for residues adjacent to the lipid matrix, and almost fourfold higher (0.15+/-0.05 A(-1)) for those oriented to the neighboring transmembrane helices. We believe that tritium incorporation data could help modeling transmembrane segment arrangement in the membrane.
authors: N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow, Russia.
authors: A V
authors: AV
authors: Shishkov
authors: A L
authors: AL
authors: Ksenofontov
authors: E N
authors: EN
authors: Bogacheva
authors: L V
authors: LV
authors: Kordyukova
authors: G A
authors: GA
authors: Badun
authors: A V
authors: AV
authors: Alekseevsky
authors: V I
authors: VI
authors: Tsetlin
authors: L A
authors: LA
authors: Baratova
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008565:Membrane Proteins / Q000737:chemistry*; D014316:Tritium
chemical_list: D008565:Membrane Proteins; D014316:Tritium; D001436:Bacteriorhodopsins