Author/Authors :
Shishkov، نويسنده , , A.V. and Ksenofontov، نويسنده , , A.L. and Bogacheva، نويسنده , , E.N. and Kordyukova، نويسنده , , L.V. and Badun، نويسنده , , G.A. and Alekseevsky، نويسنده , , A.V. and Tsetlin، نويسنده , , V.I. and Baratova، نويسنده , , L.A.، نويسنده ,
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 Å−1) for residues adjacent to the lipid matrix, and almost fourfold higher (0.15±0.05 Å−1) for those oriented to the neighboring transmembrane helices. We believe that tritium incorporation data could help modeling transmembrane segment arrangement in the membrane.
Keywords :
Attenuation coefficient , Tritium stratigraphy , bacteriorhodopsin , transmembrane helix
