Different Effects of Di- and Triphenyltin Compounds on Lipid Bilayer Dithionite Permeabilization

Abstract

Phenyltins, Lipid Bilayer, Membrane PermeabilityPhenyltins are chemicals widely used in industry, hence their occurrence in the human environment is frequent and widespread. Such compounds include hydrophobic phenyl rings bonded to positively charged tin. Tliis molecular structure makes them capable of adsorbing onto and penetrating through biological membranes, hence they are potentially hazardous. Two such compounds, diphenyltin and triphenyltin, show different steric constraints when interacting with the lipid bilayer. It has been demonstrated that these compounds are posi tioned at different locations within model lipid bilayers, causing dissimilarity in their ability to affect membrane properties. In this paper we present a study regarding the ability of these two phenyltins to facilitate the transport of S20 4-2 ions across the lipid bilayer, evaluated by a fluorescence quenching assay. In concentration range of up-to 60 [.i m those compounds do not affect lipid bilayer topology, when evaluated by vesicle size distribution. Both phenyltins facilitate the transfer of S20 4-2 across the model lipid bilayer, but the dependence of dithio nite transport on phenyltin concentration is different for both. In principle, above 20 triphenyltin is more efficient in transfering ions across the lipid bilayer than diphenyltin.

Di- and tri-phenyltin chlorides transfer across a model lipid bilayer

“…13,15,16 There is no straightforward evidence showing the transfer of such compounds through a membrane, despite the fact that indirect evidence is numerous. 11,12,17,18 The aim of our studies was to demonstrate a direct passage of the compounds across lipid membranes (and thus across the lipid phase of biological membranes). There are a variety of experimental approaches that have been employed to investigate the effect of phenyltins on the stability and organization of model and biological membranes.…”