ARGININE-BASED SURFACTANT ALTER THE BIOPHYSICAL PROPERTIES OF BACTERIAL AND MAMMALIAN VIRUS MODEL MEMBRANES

SABATIE, ALEJANDRO ENRIQUE; HERMET, MELISA; FAIT, MARÍA E.; MORCELLE, SUSANA R.; FANANI, MARÍA LAURA

Campinas, San Pablo

Congreso; 47th Annual Meeting of the Brazilian Biophysical Society; 2023

Brazilian Biophysical Society (SBBf)

Cationic surfactants have an intrinsic biocidal activity that makes them widely used active ingredients present in disinfectant formulations against viruses, bacteria and fungi. From this perspective, the aim of this work was to deepen into the biocidal mechanism of an arginine-based surfactant obtained by means of enzymatic biocatalysis in our laboratory.The effect of Nα-benzoyl-L-arginine dodecylamide (Bz-Arg-NHC12) on the biophysical properties of bacterial and mammalian virus membrane models was studied using an Escherichia coli lipid extract (ECEx) and a mammalian lipid mixture (POPC/16:0 SM/Cho 1:1:1, MVM). The first characterization carried out was the ability of Bz-Arg-NHC12 to insert itself into the lipid monolayers, evaluating the critical surface pressure. The experimental results indicate that the surfactant is capable of being inserted up to initial surface pressures of 48 ± 2 and 47 ± 2 mN/m for ECEx and MVM respectively, values that correspond to highly packed preformed monolayers. Additionally, we have determined the effect of Bz-Arg-NHC12 on the mean molecular area at 30 mN/m performing Langmuir monolayer assays using different molar percentages (10 and 20mol%) of the surfactant, but the results did not evidence any effect. At last, membrane stability was investigated measuring the surface pressure as a function of the mean molecular area during three compression-expansion cycles. We report an opposed behavior for both tested models for changes in the molecular area at 35 mN/m (maximum surface pressure measured). While ECEx monolayers showed a stability reduction in the presence of Bz-Arg-NHC12, MVM membrane evidenced an increased stability upon Bz-Arg-NHC12 incorporation in a dose-dependent manner. Similar results were found when the membrane compressibility modulus (Cs-1) was analyzed.Results evidenced that Bz-Arg-NHC12 was able to interact and insert itself in both membrane models studied, differentially modifying their biophysical properties. These distinct effects on membrane’s stability may have relevance in the biocidal mechanism of the surfactant in both, bacteria and viruses.