[Changes of dipole potential of phospholipid membranes resulted from flavonoid adsorption].

The effects of flavonoids, phloridzin, quercetin, myricetin and biochanin A on the dipole potential of planar lipid bilayers formed from dioleylphosphoethanolamine, dioleylphosphoserine, dioleoylphosphocholine, and diphytanoylphosphocholine are investigated. The characteristic parameters of the Langmuir adsorption isotherm, the maximum changes in the membrane dipole potential at an infinitely large concentration of flavonoid and its dissociation constant, which reflects the affinity of flavonoid to the membrane lipids, are determined. Modifying effects of chalcones, flavonols and isoflavones are compared.

[Transport of large organic ions through syringomycin channels in the membranes containing dipole modifiers].

The effect of the membrane dipole potential (Phid) on a conductance and a steady-state number of functioning channels formed by cyclic lipodepsipeptide syringomycin E (SRE) in bilayer lipid membranes made from phosphocholine and bathed in 0.4 M solution of sodium salts of aspartate, gluconate and chloride was shown. The magnitude of Phid was varied with the introduction to membrane bathing solutions of phloretin, which reduces the Phid, and RH 421, increasing the Phid.

[Conductance of phytotoxin channels in the presence of large organic ions].

In this study we evaluated the effect of penetrating anion size on the properties of the channels formed by cyclic lipodepsipeptide syringomycin E (SRE) in bilayer lipid membranes. Conductance and the mean lifetime of the SRE channels have been measured in 0.4 M solutions of sodium chloride, aspartate, and gluconate.

[Kinetic parameters of single ion channels and stationary conductivities of phytotoxin modified lipid bilayers].

As shown earlier, phytotoxins produced by Pseudomonas syringae pv. syringae form ion channels of "small" and "large" conductance when incorporated into planar lipid membranes. The multilevel conductance is due to cluster organization of the channels (Kaulin et al.

[Interaction between filamentous actin and lipid bilayer causes the increase of syringomycin E channel-forming activity].

The effect of filamentous (F) actin on the channel-forming activity of syringomycin E (SRE) in negatively charged and uncharged bilayer lipid membranes (BLM) was studied. F-actin did not affect the membrane conductance in the absence of SRE. No changes in SRE-induced membrane conductance were observed when the above agents were added to the same side of BLM.