title: Lanthanide modulation of the orientation of macromolecules induced by purple membrane.
abstract: Addition of Tb3+ to purple membrane (PM) suspensions changes the orientation of the menbrane normal from parallel to perpendicular with respect to the magnetic field. Residual dipolar couplings measured in protein L in the presence of PM are scaled by a factor of -1/2. NMR line broadening and cross-correlation effects induced by the addition of PM are partially reversed by Tb3+ but not by Tm3+ that has no effect on the orientation of PM. This is interpreted as the result of anisotropically restricted motion of protein L in the transiently PM-bound form.
authors.affiliation: Departament de Química Orgànica, Universitat de Barcelona, Martí i Franquès, 1-11, 08028-Barcelona, Spain.
authors.forename: Pau
authors.initials: P
authors.lastname: Bernadó
authors.forename: Renato
authors.initials: R
authors.lastname: Barbieri
authors.forename: Esteve
authors.initials: E
authors.lastname: Padrós
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
authors.forename: Miquel
authors.initials: M
authors.lastname: Pons
mesh_terms: D001426:Bacterial Proteins; D001436:Bacteriorhodopsins / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry; D018717:Purple Membrane / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C116593:L-protein, Peptococcus magnus; D028581:Lanthanoid Series Elements; D008563:Membrane Lipids; D001436:Bacteriorhodopsins