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Brazilian Journal of Medical and Biological Research

On-line version ISSN 1414-431X

Abstract

SCHWARTZ, E.F.; STUCCHI-ZUCCHI, A.; SCHWARTZ, C.A.  and  SALOMAO, L.C.. Skin secretion of Siphonops paulensis (Gymnophiona, Amphibia) forms voltage-dependent ionic channels in lipid membranes. Braz J Med Biol Res [online]. 2003, vol.36, n.9, pp. 1279-1282. ISSN 1414-431X.  http://dx.doi.org/10.1590/S0100-879X2003000900020.

The effect of the skin secretion of the amphibian Siphonops paulensis was investigated by monitoring the changes in conductance of an artificial planar lipid bilayer. Skin secretion was obtained by exposure of the animals to ether-saturated air, and then rinsing the animals with distilled water. Artificial lipid bilayers were obtained by spreading a solution of azolectin over an aperture of a Delrin cup inserted into a cut-away polyvinyl chloride block. In 9 of 12 experiments, the addition of the skin secretion to lipid bilayers displayed voltage-dependent channels with average unitary conductance of 258 ± 41.67 pS, rather than nonspecific changes in bilayer conductance. These channels were not sensitive to 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid or tetraethylammonium ion, but the experimental protocol used does not permit us to specify their characteristics.

Keywords : Siphonops; Toxin; Channel-forming toxins; Skin secretion; Ion channel; Hemolysin.

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