Clusters of protein pores in phospholipid bilayer membranes can be identified and characterized by electrochemical impedance spectroscopy

Raila, Tomas; Penkauskas, Tadas; Jankunec, Marija; Meškauskas, Tadas; Vanderah, David J.; Valinčius, Gintaras

doi:10.1016/j.electacta.2020.137179

Cited by 14 publications

(29 citation statements)

References 40 publications

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“…The full Cole-Cole plot exhibits a typical "two semi-circle" shape, which is a characteristic of disrupted integrity of tBLM (Figure S3). From the mathematical analysis by Valincius et.al, such changes in the Cole-Cole EIS plots signals the increase in the membrane defect density (Figure 6A) [38,40]. The greater the damage of the tBLM, the higher the frequency edge at which the onset of the capacitive behavior was observed.…”

Section: Hsp70 Action On Tethered Lipid Membranes In Urine Samplesmentioning

confidence: 93%

Tethered Lipid Membranes as a Nanoscale Arrangement towards Non-Invasive Analysis of Acute Pancreatitis

et al. 2021

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Extracellular heat shock proteins (HSPs) mediate immunological functions and are involved in pathologies such as infection, stress, and cancer. Here, we demonstrated the dependence of an amount of HSP70 and HSP90 in serum vs. severity of acute pancreatitis (AP) on a cohort of 49 patients. Tethered bilayer lipid membranes (tBLMs) have been developed to investigate HSPs’ interactions with tBLMs that can be probed by electrochemical impedance spectroscopy (EIS). The results revealed that HSP70 and HSP90 interact via different mechanisms. HSP70 shows the damage of the membrane, while HSP90 increases the insulation properties of tBLM. These findings provide evidence that EIS offers a novel approach for the study of the changes in membrane integrity induced by HSPs proteins. Herein, we present an alternative electrochemical technique, without any immunoprobes, that allows for the monitoring of HSPs on nanoscaled tBLM arrangement in biologics samples such us human urine. This study demonstrates the great potential of tBLM to be used as a membrane based biosensor for novel, simple, and non-invasive label-free analytical system for the prediction of AP severity.

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Section: Hsp70 Action On Tethered Lipid Membranes In Urine Samplesmentioning

confidence: 93%

Tethered Lipid Membranes as a Nanoscale Arrangement towards Non-Invasive Analysis of Acute Pancreatitis

et al. 2021

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“…The generated Bode plots are then compared to the modeled equivalent circuit leading to capacitance and conductance measurements corresponding to various membrane layers. The electrical model for the membrane may be altered as needed dependent on the experimental data, revealing additional membrane layers properties such as area defects [ 117 , 196 ].…”

Section: Electrophysiological Methods For Characterizing Lipid Membranesmentioning

confidence: 99%

Characterizing the Structure and Interactions of Model Lipid Membranes Using Electrophysiology

El-Beyrouthy

Freeman

2021

Membranes

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The cell membrane is a protective barrier whose configuration determines the exchange both between intracellular and extracellular regions and within the cell itself. Consequently, characterizing membrane properties and interactions is essential for advancements in topics such as limiting nanoparticle cytotoxicity. Characterization is often accomplished by recreating model membranes that approximate the structure of cellular membranes in a controlled environment, formed using self-assembly principles. The selected method for membrane creation influences the properties of the membrane assembly, including their response to electric fields used for characterizing transmembrane exchanges. When these self-assembled model membranes are combined with electrophysiology, it is possible to exploit their non-physiological mechanics to enable additional measurements of membrane interactions and phenomena. This review describes several common model membranes including liposomes, pore-spanning membranes, solid supported membranes, and emulsion-based membranes, emphasizing their varying structure due to the selected mode of production. Next, electrophysiology techniques that exploit these structures are discussed, including conductance measurements, electrowetting and electrocompression analysis, and electroimpedance spectroscopy. The focus of this review is linking each membrane assembly technique to the properties of the resulting membrane, discussing how these properties enable alternative electrophysiological approaches to measuring membrane characteristics and interactions.

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“…In case the electrical conductance data reflecting functional effects of PFTs or peptides on membranes is sought the tethered bilayer systems are used 5,6 . Also, both techniques, AFM and EIS, are used simultaneously or in parallel to characterize structure and function of PFTs in membranes [7][8][9][10] .…”

Section: Introductionmentioning

confidence: 99%

“…The electrochemical impedance spectroscopy (EIS) is a method of choice for detailed studies of electrical effects of PFTs in membranes. The EIS allows accessing the dielectric properties and conductance data of tBLMs (tethered bilayer membranes), and in some cases though not being structural method per se, provides insights into lateral distribution of defects in membranes [8][9][10] . 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.…”

Section: Introductionmentioning

confidence: 99%

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AI-based Atomic Force Microscopy Image Analysis Allows to Predict Electrochemical Impedance Spectra of Defects in Tethered Bilayer Membranes

Raila

Penkauskas

Jankunec

et al. 2021

Preprint

Self Cite

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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±0.10 Ω · cm 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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Clusters of protein pores in phospholipid bilayer membranes can be identified and characterized by electrochemical impedance spectroscopy

Cited by 14 publications

References 40 publications

Tethered Lipid Membranes as a Nanoscale Arrangement towards Non-Invasive Analysis of Acute Pancreatitis

Tethered Lipid Membranes as a Nanoscale Arrangement towards Non-Invasive Analysis of Acute Pancreatitis

Characterizing the Structure and Interactions of Model Lipid Membranes Using Electrophysiology

AI-based Atomic Force Microscopy Image Analysis Allows to Predict Electrochemical Impedance Spectra of Defects in Tethered Bilayer Membranes

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