Effects of Sterols on the Interaction of SDS, Benzalkonium Chloride, and A Novel Compound, Kor105, with Membranes

Abstract

Sterols change the biophysical properties of lipid membranes. Here, we analyzed how sterols affect the activity of widely used antimicrobial membrane-active compounds, sodium dodecyl sulfate (SDS) and benzalkonium chloride (BAC). We also tested a novel benzalkonium-like substance, Kor105. Our data suggest that benzalkonium and Kor105 disturb the ordering of the membrane lipid packaging, and this disturbance is dampened by cholesterol. The disturbance induced by Kor105 is stronger than that induced by BAC because of the higher rigidity of the Kor105 molecule due to a shorter linker between the phenyl group and quaternary nitrogen. On the contrary, individual SDS molecules do not cause the disturbance. Thus, in the tested range of concentrations, SDS–membrane interaction is not influenced by cholesterol. To study how sterols influence the biological effects of these chemicals, we used yeast strains lacking Lam1–4 proteins. These proteins transport sterols from the plasma membrane into the endoplasmic reticulum. We found that the mutants are resistant to BAC and Kor105 but hypersensitive to SDS. Together, our findings show that sterols influence the interaction of SDS versus benzalkonium chloride and Kor105 with the membranes in a completely different manner.

Lipophilic Cations Rescue the Growth of Yeast under the Conditions of Glycolysis Overflow

“…To address this issue experimentally, we synthesized the corresponding molecules, and keeping in mind that phosphor-organic compounds are generally not recommended for the use on humans, the novel molecules contain nitrogen instead of phosphorus ( Figure 5 A). While the compound with one phenyl group, Kor105, has recently been described by us as a potential surfactant [ 19 ], FS1 is a novel substance. As shown by Figure 4 , both compounds stimulated cell growth, with FS1 having a wider range of acting concentrations than Kor105 or C 12 TPP.…”

“…Alternatively, it is possible that the rescuing effect of BAC, as well as the rescuing effects of C 12 TPP, FS1 and Kor105, was due to its action on the plasma membrane (PM). Recently, we have shown that mutants with elevated levels of plasma membrane ergosterol are more resistant to Kor105 and C 12 TPP than the wild type [ 19 ]. Similar to that of the other two substances, the toxicity of FS1 was also found to be lower in the mutant with elevated PM ergosterol ( Figure 7 ).…”

“…Similar to that of the other two substances, the toxicity of FS1 was also found to be lower in the mutant with elevated PM ergosterol ( Figure 7 ). Our data indicate that the cations disturb the ordering of the plasma membrane lipid packaging, and this disturbance is dampened by ergosterol [ 19 ]. Possibly, ATP is consumed to repair the PM disturbance caused by the lipophilic cations.…”

Contribution of the Collective Excitations to the Coupled Proton and Energy Transport along Mitochondrial Cristae Membrane in Oxidative Phosphorylation System

“…The effect of electrical field on membrane deformation was observed, in part, by the method of inner field compensation on the bilayer membranes. Its application showed a change in the membrane thickness and capacitance when the membrane interacts with various compounds [ 85 , 86 , 87 ], including the membrane-bound proton fraction [ 3 , 4 ]. We proposed that a similar effect may also present in the MIM under proton pump functioning [ 2 ].…”

Lipid Membrane Adsorption Determines Photodynamic Efficiency of β-Imidazolyl-Substituted Porphyrins

“…The first one, the inner field compensation (IFC) method, is based on the measurement of the second harmonics of the capacitive current ( [31]). In the second method, the change of ∆ϕ b is determined from the change of the BLM conductance induced by ionophore nonactin as [32][33][34][35]…”