Avid Bioservices Inc (CDMO)

[biopharm]

Charge inversion by polyvalent ions is thought to be highly relevant for the number of biological processes, including action of drugs 19, gene delivery 20, DNA condensation7, and viral packing 21, 22.
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We demonstrate that at small voltages the gramicidin A channel in asymmetrically charged membranes displays current rectification which is close to that of a typical solid-state diode.

So flipped PS and those negative charges that Peregrine has the rights to target 100%... Happy Thanksgiving to all

The Effect of pH on the Electrical Capacitance of Phosphatidylcholine–Phosphatidylserine System in Bilayer Lipid Membrane
Monika Naumowiczcorresponding author and Zbigniew Artur Figaszewski
Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443 Bialystok, Poland
Laboratory of Electrochemical Power Sources Faculty of Chemistry, University of Warsaw, Pasteur St. 1, 02-093 Warsaw, Poland
Monika Naumowicz, Phone: [phone], Fax: [phone], Email: lp.ude.bwu@nakinom.
corresponding authorCorresponding author.
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Abstract

This paper reports measurements on the pH dependence of the electrical capacitance of lipid membranes formed by 1:1 phosphatidylcholine-phosphatidylserine mixtures. A theoretical model was developed to describe this dependence, in which the contributions of functional groups (as the active centers of adsorption of the hydrogen and hydroxide ions) to the overall membrane capacitance were assumed to be additive. The proposed model was verified experimentally using electrochemical impedance spectroscopy. The theoretical predictions agreed with the experimental results over the measured pH range. A minimum corresponding to the isoelectric point appeared in both the theoretical equation and the experimental data.
Keywords: Electrochemical impedance spectroscopy pH, Acid–base equilibria, Bilayer membrane, Phosphatidylcholine, Phosphatidylserine

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Conclusions

In conclusion, noninvasive EIS method was used to characterize the capacitive properties of the PC–PS bilayer and to provide a quantitative description of the acid–base equilibria at the interface separating the electrolyte solution and bilayer. The electrical capacitance of the analyzed bilayer had a minimum value around pH 4.2. The value of the capacitance increased as the pH of the solution decreased or increased.

Therefore, pH appears to play an important role in setting the electrical properties of bilayer lipid membranes. This information may be useful for investigating the functional properties of lipid membranes and membrane proteins under aqueous pH stress.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3950607/