[13] Lipids of purple membrane from extreme halophiles and of methanogenic bacteria

Kates, M.; Kushwaha, S. C.; Sprott, G. Dennis

doi:10.1016/0076-6879(82)88016-6

Cited by 156 publications

(116 citation statements)

References 27 publications

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“…For reconstitution into polar lipids (preparation as described in Ref. 27) from purple membrane (PML), the mixtures were shaken (16 h at 4°C in the dark) in 10 mM Tris-HCl (pH 8), 1 M NaCl containing either a 40-fold (low lipid content, 90 lipids per 2:2 complex, standard conditions if not given in situ) or a 400-fold (high lipid content, 900 lipids per 2:2 complex) molar excess of lipids as well as detergent-adsorbing Bio-Beads (SM-2; 10 mg/mg of dodecylmaltoside; Roche Applied Science). After filtration, the reconstituted proteins were pelleted by centrifugation at 20,000 ϫ g and resuspended in 10 mM Tris-HCl (pH 8), 150 mM KCl.…”

Section: Methodsmentioning

confidence: 99%

Salt-driven Equilibrium between Two Conformations in the HAMP Domain from Natronomonas pharaonis

Doebber

Bordignon

Klare

et al. 2008

Journal of Biological Chemistry

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HAMP domains (conserved in histidine kinases, adenylyl cyclases, methyl-accepting chemotaxis proteins, and phosphatases) perform their putative function as signal transducing units in diversified environments in a variety of protein families. Here the conformational changes induced by environmental agents, namely salt and temperature, on the structure and function of a HAMP domain of the phototransducer from Natronomonas pharaonis (NpHtrII) in complex with sensory rhodopsin II (NpSRII) were investigated by site-directed spin labeling electron paramagnetic resonance. A series of spin labeled mutants were engineered in NpHtrII 157 , a truncated analog containing only the first HAMP domain following the transmembrane helix 2. This truncated transducer is shown to be a valid model system for a signal transduction domain anchored to the transmembrane light sensor NpSRII. The HAMP domain is found to be engaged in a "two-state" equilibrium between a highly dynamic (dHAMP) and a more compact (cHAMP) conformation. The structural properties of the cHAMP as proven by mobility, accessibility, and intra-transducer-dimer distance data are in agreement with the four helical bundle NMR model of the HAMP domain from Archaeoglobus fulgidus.

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Section: Methodsmentioning

confidence: 99%

Salt-driven Equilibrium between Two Conformations in the HAMP Domain from Natronomonas pharaonis

Doebber

Bordignon

Klare

et al. 2008

Journal of Biological Chemistry

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“…While these observations are compatible with standard biophysical formalism, a surprising result was recorded when the protons were detected by an indicator that resides in the bulk. Pyranine (8-hydroxypyrene-l,3,6-trisulfonate) (~OH) does not adsorb to negatively charged purple membranes [9,10], thus its protonation measures how fast the acidic pulse propagates to the bulk. The rate of this reaction was measured by many research groups [3 8].…”

Section: Introductionmentioning

confidence: 99%

Quantitative evaluation of the dynamics of proton transfer from photoactivated bacteriorhodopsin to the bulk

Nachliel

Gutman

1996

FEBS Letters

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It has been reported by many research groups that protons released during the photocycle of bacteriorhodopsin are detected by surface bound indicators much faster than by indicators in the bulk. In this study we used numerical simulation of chemical reaction's dynamics for analyzing the delayed appearance of protons in the bulk. The results indicate that the low pK surface groups of the membrane, which form an undilutable concentrated matrix of proton binding sites, retain the protons in this space according to the mass action law. The main sites for proton accumulation are the cluster of carboxylates on the cytoplasmic side of the membrane. The protonation of an indicator in the bulk does not proceed by its reaction with free proton, but rather through self-diffusion of the indicator to the membrane and abstraction of proton from the protonated surface group. The detailed mechanisms which correspond with these reactions are reported.

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“…Purple membrane is a constituent of the inner membrane of H. salinarium and consists of 75% bacteriorhodopsin (M r 26,500), a light-driven proton pump, and of 25% lipids (Kates et al, 1982). Bacteriorhodopsin molecules are naturally arranged in a highly ordered 2D trigonal lattice (a 5 b 5 6.2 nm) and consist of seven transmembrane a-helices (Henderson et al, 1990) surrounding the photoreactive retinal (Jubb et al, 1984).…”

Section: Fig 10mentioning

confidence: 99%

Adsorption of Biological Molecules to a Solid Support for Scanning Probe Microscopy

Müller

Amrein

Engel

1997

Journal of Structural Biology

286

204

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[13] Lipids of purple membrane from extreme halophiles and of methanogenic bacteria

Cited by 156 publications

References 27 publications

Salt-driven Equilibrium between Two Conformations in the HAMP Domain from Natronomonas pharaonis

Salt-driven Equilibrium between Two Conformations in the HAMP Domain from Natronomonas pharaonis

Quantitative evaluation of the dynamics of proton transfer from photoactivated bacteriorhodopsin to the bulk

Adsorption of Biological Molecules to a Solid Support for Scanning Probe Microscopy

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