[Channel formation properties of black widow venom]

Black widow venom in the concentration 1--10 mkg/ml added on one side of the bilayer of common bovine brain phospholipids induces the formation of conductivity channels with high cation-anion selectivity with the number of cation transfer for K+, Ca2+, Sr2+, Mg2+, Na+, Cs+, Li+ equaling 0.98, 0.97, 0.96, 0.94. 0.88. 0.82, 0.82 correspondingly (at pH = 7.5). At pH less than 3.5 the channels are slightly selective for anions (the number of cation transfer 0.4). Potential-dependence of the channels is found, which is explained by microstructural reconstruction of their protein complex.