Lipid membranes supported on optically transparent nanosilicas: Synthesis and application in characterization of protein-membrane interactions

Supported lipid membranes are widely used platforms which serve as simplified models of cell membranes. Among numerous methods used for preparation of planar lipid films, self-assembly of bicelles appears to be promising strategy. Therefore, in this paper we have examined the mechanism of formation and the electrochemical properties of lipid films deposited onto thioglucose-modified gold electrodes from bicellar mixtures. It was found that adsorption of the bicelles occurs by replacement of interfacial water and it leads to formation of a double bilayer structure on the electrode surface. The resulting lipid assembly contains numerous defects and pinholes which affect the permeability of the membrane for ions and water. Significant improvement in morphology and electrochemical characteristics is achieved upon freeze–thaw treatment of the deposited membrane. The lipid assembly is rearranged to single bilayer configuration with locally occurring patches of the second bilayer, and the number of pinholes is substantially decreased. Electrochemical characterization of the lipid membrane after freeze–thaw treatment demonstrated that its permeability for ions and water is significantly reduced, which was manifested by the relatively high value of the membrane resistance.

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Prothrombinase complex assembly. Contributions of protein-protein and protein-membrane interactions toward complex formation.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)39652-8 ◽

1990 ◽

Vol 265 (7) ◽

pp. 3708-3718

Author(s):

S Krishnaswamy

Keyword(s):

Complex Formation ◽

Membrane Interactions ◽

Complex Assembly ◽

Prothrombinase Complex ◽

Protein Membrane

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Optically transparent vertical silicon nanowire arrays for live-cell imaging

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00795-7 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Roey Elnathan ◽

Andrew W. Holle ◽

Jennifer Young ◽

Marina A. George ◽

Omri Heifler ◽

...

Keyword(s):

High Efficiency ◽

Silicon Nanowire ◽

Live Cell ◽

Si Nanowires ◽

Contrast Imaging ◽

Silicon Nanowire Arrays ◽

Transparent Substrate ◽

Optically Transparent ◽

Vertically Aligned

AbstractProgrammable nano-bio interfaces driven by tuneable vertically configured nanostructures have recently emerged as a powerful tool for cellular manipulations and interrogations. Such interfaces have strong potential for ground-breaking advances, particularly in cellular nanobiotechnology and mechanobiology. However, the opaque nature of many nanostructured surfaces makes non-destructive, live-cell characterization of cellular behavior on vertically aligned nanostructures challenging to observe. Here, a new nanofabrication route is proposed that enables harvesting of vertically aligned silicon (Si) nanowires and their subsequent transfer onto an optically transparent substrate, with high efficiency and without artefacts. We demonstrate the potential of this route for efficient live-cell phase contrast imaging and subsequent characterization of cells growing on vertically aligned Si nanowires. This approach provides the first opportunity to understand dynamic cellular responses to a cell-nanowire interface, and thus has the potential to inform the design of future nanoscale cellular manipulation technologies.

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Fluorescence of membrane-bound tryptophan octyl ester: a model for studying intrinsic fluorescence of protein-membrane interactions

Biophysical Journal ◽

10.1016/s0006-3495(95)79924-6 ◽

1995 ◽

Vol 69 (2) ◽

pp. 506-517 ◽

Cited By ~ 52

Author(s):

A.S. Ladokhin ◽

P.W. Holloway

Keyword(s):

Intrinsic Fluorescence ◽

Membrane Interactions ◽

Protein Membrane ◽

Membrane Bound

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Specific protein-membrane interactions promote packaging of metallo-β-lactamases into outer membrane vesicles

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00507-21 ◽

2021 ◽

Author(s):

Carolina López ◽

Alessio Prunotto ◽

Guillermo Bahr ◽

Robert A. Bonomo ◽

Lisandro J. González ◽

...

Keyword(s):

Outer Membrane ◽

Electrostatic Interactions ◽

Active Form ◽

Membrane Vesicles ◽

Specific Protein ◽

Outer Membrane Vesicles ◽

Soluble Enzyme ◽

Membrane Interactions ◽

Resistance Determinants ◽

Protein Membrane

Outer membrane vesicles (OMVs) act as carriers of bacterial products such as plasmids and resistance determinants, including metallo-β-lactamases. The lipidated, membrane-anchored metallo-β-lactamase NDM-1 can be detected in Gram-negative OMVs. The soluble domain of NDM-1 also forms electrostatic interactions with the membrane. Herein, we show that these interactions promote its packaging into OMVs produced by Escherichia coli . We report that favorable electrostatic protein-membrane interactions are also at work in the soluble enzyme IMP-1, while being absent in VIM-2. These interactions correlate with an enhanced incorporation of IMP-1 compared to VIM-2 into OMVs. Disruption of these interactions in NDM-1 and IMP-1 impairs their inclusion into vesicles, confirming their role in defining the protein cargo in OMVs. These results also indicate that packaging of metallo-β-lactamases into vesicles in their active form is a common phenomenon that involves cargo selection based on specific molecular interactions.

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