Precise Size Determination of Amphotericin B and Nystatin Channels Formed in Erythrocyte and Liposomal Membranes Based on Osmotic Protection Experiments

Osmotic Effects Induced by Pore-Forming Agent Nystatin: From Lipid Vesicles to the Cell

“…These transmembrane pores, with their effective radii that are comparable to the size of small molecules, have size-selective properties [8–10]. They increase the plasma membrane permeability, especially for ions and small molecules, which causes a disturbance in cellular electrochemical gradients and ultimately leads to cell lysis [1].…”

Molecular organization of antifungal antibiotic amphotericin B in lipid monolayers studied by means of Fluorescence Lifetime Imaging Microscopy

“…According to a popular conviction AmB present in biomembranes associates into molecular aggregates in the form of transmembrane pores that affect physiological ion transport [4][5][6][7][8]. The concept that such structures are formed more efficiently in the presence of ergosterol, the sterol present in the membranes of fungi, than in the presence of cholesterol is a key paradigm of selectivity of AmB.…”

“…The concept that such structures are formed more efficiently in the presence of ergosterol, the sterol present in the membranes of fungi, than in the presence of cholesterol is a key paradigm of selectivity of AmB. It has been also proposed that selectivity toward cells of fungi is based upon a difference of the radii of porous structures of AmB binding ergosterol and cholesterol [6,9]. On the other hand, very recent reports show that alternatively both the biological action of the drug as well as toxic side effects may be directly related to the effect of AmB on physical properties of the membranes [10][11][12][13].…”

In Situ Monitoring of Photodynamic Inactivation of the Membrane Functions of Bacteria Using Electrochemical Sensors

“…[1][2][3][4] We were interested in monitoring the time-dependent process of this damage, using electrochemical sensors, such as ion-selective and oxygen electrodes. Although these sensors are widely used to analyze the actions of biologically-active substances in living cells, [5][6][7][8] including photodynamic action, 9 no study has reported the in situ monitoring of the photodynamic inactivation of bacteria under photo-irradiation.…”

“…All of the measurements were performed with stirring in a thermostat adjusted to 37 C. The K + and TPP + electrodes were constructed as reported previously. 5,6,14 Melittin (final concentration, 10 μM) was used to disrupt the cytoplasmic membrane of S. aureus cells in order to determine both the 100% level of the K + efflux from bacteria and the 0% level of the membrane potential (the complete dissipation of membrane potential). 5,15 The maximal uptake of TPP + , observed just prior to photo-irradiation, was defined as 100% membrane potential.…”