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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Location of the Positive Charges in Cationic Amphiphiles Modulates Their Mechanism of Action against Model Membranes

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Author(s):
Almeida, Marcio M. [1] ; Perez, Katia R. [1] ; Faig, Allison [2] ; Uhrich, Kathryn E. [2, 3] ; Riske, Karin A. [1]
Total Authors: 5
Affiliation:
[1] Univ Fed Sao Paulo, Dept Biophys, Sao Paulo - Brazil
[2] Rutgers State Univ, Dept Chem & Chem Biol, Piscataway, NJ 08854 - USA
[3] Univ Calif Riverside, Dept Chem, Riverside, CA 92521 - USA
Total Affiliations: 3
Document type: Journal article
Source: Langmuir; v. 35, n. 43, p. 14117-14123, OCT 29 2019.
Web of Science Citations: 0
Abstract

Synthetic cationic amphiphiles (CAms) with physicochemical properties similar to antimicrobial peptides are promising molecules in the search for alternative antibiotics to which pathogens cannot easily develop resistance. Here, we investigate two types of CAms based on tartaric acid and containing two hydrophobic chains (of 7 or 11 carbons) and two positive charges, located either at the end of the acyl chains (bola-like, B7 and B11) or at the tartaric acid backbone (gemini-like, G7 and G11). The interaction of the CAms with biomimetic membrane models (anionic and neutral liposomes) was studied with zeta potential and dynamic light scattering measurements, isothermal titration calorimetry, and a fluorescent-based leakage assay. We show that the type of molecule determines the mechanism of action of the CAms. Gemini-like molecules (G7 and G11) interact mainly via electrostatics (exothermic process) and reside in the external vesicle leaflet, altering substantially the vesicle surface potential but not causing significant membrane lysis. On the other hand, the interaction of bola-like CAms (B7 and B11) is endothermic and thus entropy-driven, and these molecules reach both membrane leaflets and cause substantial membrane permeabilization, likely after clustering of anionic lipids. The lytic ability is clearly higher against anionic membranes as compared with neutral membranes. Within each class of molecule, longer alkyl chains (i.e., B11 and G11) exhibit higher affinity and lytic ability. Overall, the molecule B11 exhibits a high potential as antimicrobial agent, since it has a high membrane affinity and causes substantial membrane permeabilization. (AU)

FAPESP's process: 16/13368-4 - Nanostructured systems: from membrane biomimetic models to carriers of bioactives
Grantee:Karin Do Amaral Riske
Support Opportunities: Research Projects - Thematic Grants