Physicochemical Characterization of Sparsely Tethered Bilayer Lipid Membranes: Structure of Submembrane Water and Nanomechanical Properties

Dziubak, Damian; Sęk, Sławomir

doi:10.1002/celc.202100721

Cited by 8 publications

(3 citation statements)

References 36 publications

(69 reference statements)

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“…To predict the expected direction of the peaks of the single-channel currents, the actual transmembrane potential must be determined. The potential of zero free charge (PZFC) in sparsely tethered membranes has been reported to be approximately 0.3 V . From this, the transmembrane potential can be determined using the following equation φ trans = E applied − E PZFC …”

Section: Resultsmentioning

confidence: 99%

Activity of Single Insect Olfactory Receptors Triggered by Airborne Compounds Recorded in Self-Assembled Tethered Lipid Bilayer Nanoarchitectures

Kleinheinz,

D’Onofrio,

Carraher

et al. 2023

ACS Appl. Mater. Interfaces

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Membrane proteins are among the most difficult to study as they are embedded in the cellular membrane, a complex and fragile environment with limited experimental accessibility. To study membrane proteins outside of these environments, model systems are required that replicate the fundamental properties of the cellular membrane without its complexity. We show here a self-assembled lipid bilayer nanoarchitecture on a solid support that is stable for several days at room temperature and allows the measurement of insect olfactory receptors at the single-channel level. Using an odorant binding protein, we capture airborne ligands and transfer them to an olfactory receptor from Drosophila melanogaster (OR22a) complex embedded in the lipid membrane, reproducing the complete olfaction process in which a ligand is captured from air and transported across an aqueous reservoir by an odorant binding protein and finally triggers a ligand-gated ion channel embedded in a lipid bilayer, providing direct evidence for ligand capture and olfactory receptor triggering facilitated by odorant binding proteins. This model system presents a significantly more user-friendly and robust platform to exploit the extraordinary sensitivity of insect olfaction for biosensing. At the same time, the platform offers a new opportunity for label-free studies of the olfactory signaling pathways of insects, which still have many unanswered questions.

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Section: Resultsmentioning

confidence: 99%

Activity of Single Insect Olfactory Receptors Triggered by Airborne Compounds Recorded in Self-Assembled Tethered Lipid Bilayer Nanoarchitectures

Kleinheinz,

D’Onofrio,

Carraher

et al. 2023

ACS Appl. Mater. Interfaces

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“…SEIRAS method provides detailed molecular information on the structure of molec ular assemblies on the gold surface in situ [47,48]. Characteristic of SEIRAS, the rapid plasmon-enhanced local electric field decrease along the surface normal that makes the technique particularly useful in SAM and artificial lipid-membrane studies [49][50][51][52]. More over, the spectral contribution from the bulk water can be almost completely cancelled by constructing a perturbation-difference spectrum (electric field, pH, etc.…”

Section: Seirasmentioning

confidence: 99%

Effect of pH on Electrochemical Impedance Response of Tethered Bilayer Lipid Membranes: Implications for Quantitative Biosensing

Shivabalan,

Ambrulevicius,

Talaikis

et al. 2023

Chemosensors

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Tethered bilayer lipid membranes (tBLMs) are increasingly used in biosensor applications where electrochemical impedance spectroscopy (EIS) is the method of choice for amplifying and recording the activity of membrane-damaging agents such as pore-forming toxins or disrupting peptides. While the activity of these biological agents may depend on the pH of the analytes, there is increasing evidence that the sensitivity of tethered bilayer sensors depends on the pH of the solutions. In our study, we addressed the question of what are the fundamental reasons for the variability of the EIS signal of the tBLMs with pH. We designed an experiment to compare the EIS response of tBLMs with natural membrane defects and two different membrane disruptors: vaginolysin and melittin. Our experimental design ensured that the same amount of protein and peptide was present in the tBLMs, while the pH was varied by replacing the buffers with different pH values. Using a recently developed EIS data analysis algorithm from our research group, we were able to demonstrate that, in contrast to previous literature which relates the variability of tBLM, EIS response to the variation in defect density, the main reason for the observed variability in EIS response is the change in the sub-membrane properties of tBLMs with pH. Using surface-enhanced infrared absorption spectroscopy (SEIRAS), we have shown that pH changes from neutral to slightly acidic leads to an expulsion of water, presumably bound to ions, from the sub-membrane reservoir, resulting in a marked decrease in the carrier concentration and specific conductance of the sub-membrane reservoir. Such a decrease is recorded by the EIS as a decrease in the conductance of the tBLM complex and affects the sensitivity of a biosensor. Our data provide important evidence of pH-sensitive effects that should be considered in both the development and operation of biosensors.

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“…Nevertheless, the study of EDL usually ignores the structure, orientation, and hydrogen bonding network of solvent molecules, even if a steep drop in the dielectric constant of water molecules from 80 in the bulk solution to ∼2 in the interface layer occurs due to the decrease in the degree of rotational freedom of water dipoles . While the molecular characteristics of hydration at the phospholipid membranes interface have been widely revealed by vibrational sum frequency generation (VSFG) − and IR spectroscopy, − the molecular-level influence of water on the electrostatic properties of the interface, including potential, current, and capacitance, is still ambiguous.…”

mentioning

confidence: 99%

Molecular Nature of Structured Water in the Light-Induced Interfacial Capacitance Changes at the Bioelectric Interface

Zhen

et al. 2021

J. Phys. Chem. Lett.

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Uncovering the function of structured water in the interfacial capacitance at the molecular level is the basis for the development of the concept and model of the electric double layer; however, the limitation of the available technology makes this task difficult. Herein, using surface-enhanced infrared absorption spectroscopy combined with electrochemistry, we revealed the contribution of the cleavage of loosely bonded tetrahedral water to the enhancement of model membrane capacitance. Upon further combination with ionic perturbation, we found that the interface hydrogen bonding environment in the stern layer was greatly significant for the light-induced cleavage of tetrahedral water and thus the conversion of optical signals into electrical signals. Our work has taken an important step toward gaining experimental insight into the relationship between water structure and capacitance at the bioelectric interface.

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Physicochemical Characterization of Sparsely Tethered Bilayer Lipid Membranes: Structure of Submembrane Water and Nanomechanical Properties

Cited by 8 publications

References 36 publications

Activity of Single Insect Olfactory Receptors Triggered by Airborne Compounds Recorded in Self-Assembled Tethered Lipid Bilayer Nanoarchitectures

Activity of Single Insect Olfactory Receptors Triggered by Airborne Compounds Recorded in Self-Assembled Tethered Lipid Bilayer Nanoarchitectures

Effect of pH on Electrochemical Impedance Response of Tethered Bilayer Lipid Membranes: Implications for Quantitative Biosensing

Molecular Nature of Structured Water in the Light-Induced Interfacial Capacitance Changes at the Bioelectric Interface

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