Single Molecules as Probes of Lipid Membrane Microenvironments

Chad E. Talley; Robert C. Dunn

doi:10.1021/jp992639z

Characterization of Photophysics and Mobility of Single Molecules in a Fluid Lipid Membrane

The Journal of Physical Chemistry ◽

10.1021/j100049a030 ◽

1995 ◽

Vol 99 (49) ◽

pp. 17662-17668 ◽

Cited By ~ 167

Author(s):

Th. Schmidt ◽

G. J. Schuetz ◽

W. Baumgartner ◽

H. J. Gruber ◽

H. Schindler

Keyword(s):

Lipid Membrane ◽

Single Molecules

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Single molecules in the dark

Nature Cell Biology ◽

10.1038/ncb1952 ◽

2009 ◽

Vol 11 (S1) ◽

pp. S19-S19 ◽

Cited By ~ 5

Author(s):

Daniel Evanko

Keyword(s):

Single Molecules

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Chapter 2b: The molecular antigenic structure of the TBEV

Tick-borne encephalitis - The Book ◽

10.33442/26613980_2b-3 ◽

2020 ◽

Keyword(s):

Conformational Changes ◽

Neutralizing Antibodies ◽

Lipid Membrane ◽

Cell Entry ◽

Antigenic Structure ◽

E Proteins ◽

Amino Acid Sequence Level ◽

Endosomal Membrane ◽

E Protein ◽

Golgi Network

TBEV-particles are assembled in an immature, noninfectious form in the endoplasmic reticulum by the envelopment of the viral core (containing the viral RNA) by a lipid membrane associated with two viral proteins, prM and E. Immature particles are transported through the cellular exocytic pathway and conformational changes induced by acidic pH in the trans-Golgi network allow the proteolytic cleavage of prM by furin, a cellular protease, resulting in the release of mature and infectious TBE-virions. The E protein controls cell entry by mediating attachment to as yet ill-defined receptors as well as by low-pH-triggered fusion of the viral and endosomal membrane after uptake by receptor-mediated endocytosis. Because of its key functions in cell entry, the E protein is the primary target of virus neutralizing antibodies, which inhibit these functions by different mechanisms. Although all flavivirus E proteins have a similar overall structure, divergence at the amino acid sequence level is up to 60 percent (e.g. between TBE and dengue viruses), and therefore cross-neutralization as well as (some degree of) cross-protection are limited to relatively closely related flaviviruses, such as those constituting the tick-borne encephalitis serocomplex.

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Multifunctional far-field luminescence nanoscope for studying single molecules and quantum dots

Uspekhi Fizicheskih Nauk ◽

10.3367/ufnr.2018.06.038461 ◽

2018 ◽

Vol 189 (03) ◽

pp. 312-322 ◽

Cited By ~ 1

Author(s):

Ivan Yu. Eremchev ◽

M.Yu. Eremchev ◽

Andrei V. Naumov

Keyword(s):

Quantum Dots ◽

Single Molecules ◽

Far Field

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1033 - Characterization of lignocellulose-degrading potentials in Antarctic King Sejong station soil using single molecules real-time metagenomic sequencing

10.26226/morressier.5b5199c1b1b87b000ecee739 ◽

2018 ◽

Author(s):

Han Na Oh

Keyword(s):

Real Time ◽

Single Molecules ◽

Metagenomic Sequencing

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Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

10.26434/chemrxiv.8282204.v1 ◽

2019 ◽

Author(s):

Jiajun Wang ◽

Rémi Terrasse ◽

Jayesh Arun Bafna ◽

Lorraine Benier ◽

Mathias Winterhalter

Keyword(s):

Outer Membrane ◽

Lipid Membrane ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Multi Drug Resistance ◽

Gram Negative Bacteria ◽

Membrane Channels ◽

Gram Negative ◽

Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from Escherichia coli, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (kon) and lower dissociation (koff) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

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