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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:15 |
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Conference: Bucharest University Faculty of Physics 2024 Meeting
Section: Biophysics; Medical Physics
Title:
Effects of Gramicidin A on membrane fluidity
Authors:
Diana-Lavinia STAN (1,2), Mihaela BACALUM (2)
Affiliation:
1) University of Bucharest, Faculty of Physics, 405 Atomistilor Street, P.O. Box MG-11, 077125 Magurele, Romania
2) “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Măgurele, Romania
E-mail
diana.stan@nipne.ro;
bmihaela@nipne.ro
Keywords:
Gramicidin A, membrane fluidity
Abstract:
In recent years, antimicrobial peptides have garnered significant attention due to their anti-cancer properties. Among these peptides, Gramicidin A (GA) has been of particular interest for its ability to form selective ion channels within cell membranes (1). Utilizing Laurdan, an organic compound that is sensitive to changes in polarity (2), the alterations in membrane fluidity subsequent to GA incorporation was investigated. This research started with analyses on membrane models from POPC in which we studied both temperature variation (from 10 ℃ to 60 ℃ in step of 10 ℃) at a constant concentration of GA (1 𝜇M and 25 𝜇M) and the variation in the concentration of peptides (1 𝜇M, 2.5𝜇M, 5 𝜇M, 10 𝜇M, 15 𝜇M, 20 𝜇M, 25 𝜇M) at a fixed temperature (20 ℃ and 37 ℃). The same analysis of the variation of the GA concentration was also examined for two distinct cell lines, HCT-116 and HT 29. Further, the study was expanded to include the impact of nanoparticles with GA on membrane fluidity. Finally, we assessed cell viability post-treatment with GA and the aforementioned nanoparticles. Following the generalized polarization (GP) calculation it can be concluded that the peptides have been inserted into the membrane.
References:
(1) Kelkar D. A., Chattopadhyay A., The gramicidin ion channel: a model membrane protein, Biochimica et Biophysica Acta (BBA)-Biomembranes 1768, 9, 2011-2025, 2007
(2) Parasassi T., Gratton E., Membrane lipid domains and dynamics as detected by Laurdan fluorescence, Journal of fluorescence 5, 59-69, 1995
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