[Initiation of anion-selective ionic channels in bilayer membranes at lipid phase transitions].

A study was carried out to electric parameters of single ionic channels initiated at phase transition of bromidmetilate 1,2-distearoyl-rac-glycero-3-(O-beta-dimethylaminoethyl)-methylphosphonate, whose molecules under conditions given below are possibly charged. It has been shown that changes of transmembrane current appear at phase transition temperature. Comparison between ionic selectivity of channels initiated at Tph.

The appearance of single-ion channels in unmodified lipid bilayer membranes at the phase transition temperature.

Ion-specific channels in artificial membranes have been formed by the addition of gramicidin A, alamethicin, polyene antibiotics and some proteins to the solution surrounding the bilayer lipid membrane. Until now there have been no reports of single-ion channels in unmodified lipid membranes. We have now studied the electrical conductance of planar lipid bilayers membranes made of synthetic distearoylphosphorylcholine (DSPC).

[Free radicals formed during UV-irradiation of biological membrane lipids].

Formation of free radicals under UV-irradiation of egg phosphatidyl choline, and synthetic phosphatidyl cholines and their analogs, as well as of their model compounds was studied. When saturated fat lipids are UV-irradiated radicals--CH2CH2 are accumulated at the expense of the breakage of--CH2CH2--COOH-bond. Radicals CH3--OCH2, HCO are formed in aminoalcohols due to the breakage of --OCH2--CH2N+(CH3)3- and--CH2--N+(CH3)3-bonds.

[Ion permeability of bilayer membranes formed from synthetic phospholipids in the phase transition region].

Ion permeability of black lipid membranes formed from synthetic phospholipids has been studied. The resistance of BLM formed from phosphatidylcholine, tiophosphatidylcholine, threealkylphosphate and threealkyltiophosphate was 10(7)--10(8) Ohm.cm2.