Phospholipid Sensors for Detection of Bacterial Pore-Forming Toxins

Valinčius, Gintaras; Budvytytė, Rima; Penkauskas, Tadas; Plečkaitytė, Milda; Žvirblienė, Aurelija

doi:10.1149/06401.0117ecst

Cited by 7 publications

(4 citation statements)

References 10 publications

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“…An artificial phospholipid bilayer membrane system on solid support is a convenient platform for reconstitution of proteins (peptides, toxins, enzymes) and investigation for membrane-protein interactions. [1][2][3] Such system could be used as a sensing platform for different bacterial toxins 4,5 A lot of studies of phospholipid membranes are carried out using thin film gold as solid support. [6][7][8][9][10] Atomically flat surface of sputtered Au is suitable for atomic force microscopy (AFM), 8 ellipsometry, 11 surface plasmon resonance (SPR) 8,12 electrochemical impedance spectroscopy (EIS) [7][8][9]13 studies.…”

Section: Supplementary Materials For This Article Is Available Onlinementioning

confidence: 99%

Tethered Bilayer Membrane Formation on Silanized Fluorine Doped Tin Oxide Surface

Gabriūnaitė

Valinčius

Žilinskas

et al. 2022

J. Electrochem. Soc.

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Silane compound was synthesized via click chemistry and a mixture of synthesis products without purification was used to form the self-assembled monolayers on metal oxide conducting films of fluorine doped tin oxide (FTO). Silanized FTO surfaces triggered rupture of multilamellar vesicles and formed electrically insulating tethered bilayer membranes (tBLMs). In contrast to well-known hybrid bilayer membranes on silane monolayers such as ones formed from octadecyltrichlorosilane, tBLMs on FTO contained water-ion reservoir between solid surface and phospholipid bilayer sheet. They demonstrated biological relevance and ability to reconstitute the pore-forming protein channels such as α-hemolysin from Staphylococcus aureus and melittin. The addition of cholesterol to tBLMs decreased the membrane-damaging effect of melittin, while the opposite was observed in the case of α-hemolysin. The tBLMs can be regenerated multiple times without losing their functionality. The described methodology (both synthesis and formation of anchor monolayer) can be extended to any oxide film surface by properly adjusting chemical composition of molecular anchor and silanization conditions. This makes the proposed biomimetic membrane system attractive for various applications including biomedical sensors for the detection of pore-forming toxins.

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Section: Supplementary Materials For This Article Is Available Onlinementioning

confidence: 99%

Tethered Bilayer Membrane Formation on Silanized Fluorine Doped Tin Oxide Surface

Gabriūnaitė

Valinčius

Žilinskas

et al. 2022

J. Electrochem. Soc.

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“…EIS methodology allows VLY to be detected down to 0.5 nM concentration. Valincius et al [ 198 ] used this stBLM as a sensor platform to detect the activity of pore‐forming toxins, with regard to vaginolysin. The electrochemical setup consisted of six independent 250‐300 μL vials.…”

Section: Tethered Blms Anchored To Solid Supportsmentioning

confidence: 99%

Functional activity of peptide ion channels in tethered bilayer lipid membranes: Review

Guidelli

Becucci²

2021

Electrochemical Science Adv

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Ion transport across biomembranes plays a major role in living cells. This fundamental function is normally carried out by molecules with both a hydrophobic and a hydrophilic side (amphiphilic molecules), which aggregate within the membrane forming a hydrophilic pore (the ion channel) permitting the selective translocation of permeant ions. Countless papers report the conformation of these ion channels in lipid vesicles using several techniques, such as circular dichroism and solid‐state NMR spectroscopies. However, the functional activity of ion channels can only be investigated by varying the transmembrane potential. This is also the situation in which ion channels operate in commercialized drugs with intracellular targeting activities, of great interest in pharmaceutical research. A suitable biomimetic membrane must consist of a conducting or semiconducting support, whose “heart” is a lipid bilayer in contact with the aqueous solution of interest on one side. The other side must comprise a hydrophilic region thick enough to completely decouple the lipid bilayer from the support, giving rise to a “tethered bilayer lipid membrane” (tBLM). This review aims to describe the numerous efforts made over time to approach this goal, the most recent achievements, and the perspectives of future development. Special emphasis will be placed on the electrochemical aspects of tBLMs, and a qualitative overview of the main optical and scanning probe techniques employed will be provided.

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“…So far, however, there were no attempts to quantitatively relate structural data obtained by AFM and the membrane conductance data measured by EIS, even though experimental capabilities to apply both techniques on the same membrane samples are straightforward. Such comparative measurements would be of great value in studying function of both single and multiple ensembles of membrane damaging protein entities as well as in developing precision biosensors based on tBLMs 11 , 12 .…”

Section: Introductionmentioning

confidence: 99%

AI-based atomic force microscopy image analysis allows to predict electrochemical impedance spectra of defects in tethered bilayer membranes

Raila

Penkauskas

Jankunec

et al. 2022

Sci Rep

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Atomic force microscopy (AFM) image analysis of supported bilayers, such as tethered bilayer membranes (tBLMs) can reveal the nature of the membrane damage by pore-forming proteins and predict the electrochemical impedance spectroscopy (EIS) response of such objects. However, automated analysis involving pore detection in such images is often non-trivial and can require AI-based object detection techniques. The specific object-detection algorithm we used to determine the defect coordinates in real AFM images was a convolutional neural network (CNN). Defect coordinates allow to predict the EIS response of tBLMs populated by the pore-forming toxins using finite element analysis (FEA) modeling. We tested if the accuracy of the CNN algorithm affected the EIS spectral features sensitive to defect densities and other physical parameters of tBLMs. We found that the EIS spectra can be predicted sufficiently well, however, systematic errors of characteristic spectral points were observed and need to be taken into account. Importantly, the comparison of predicted EIS curves with experimental ones allowed to estimate important physical parameters of tBLMs such as the specific resistance of submembrane reservoir. This reservoir separates phospholipid bilayer from the solid support. We found that the specific resistance of the reservoir amounts to $$10^{4.25 \pm 0.10}$$ 10 4.25 ± 0.10 $$\Omega \cdot cm$$ Ω · c m which is approximately two orders of a magnitude higher compared to the specific resistance of the buffer bathing tBLMs studied in this work. We hypothesize that such effect may be related in part due to decreased concentration of ionic carriers in the submembrane due to decreased relative dielectric permittivity in this region.

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Phospholipid Sensors for Detection of Bacterial Pore-Forming Toxins

Cited by 7 publications

References 10 publications

Tethered Bilayer Membrane Formation on Silanized Fluorine Doped Tin Oxide Surface

Tethered Bilayer Membrane Formation on Silanized Fluorine Doped Tin Oxide Surface

Functional activity of peptide ion channels in tethered bilayer lipid membranes: Review

AI-based atomic force microscopy image analysis allows to predict electrochemical impedance spectra of defects in tethered bilayer membranes

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