A Characeae Cells Plasma Membrane as a Model for Selection of Bioactive Compounds and Drugs: Interaction of HAMLET-Like Complexes with Ion Channels of Chara corallina Cells Plasmalemma

Interaction of a HAMLET-like La–OA cytotoxic complex (human α-lactalbumin-oleic acid) and its constituents with the excitable plasmalemma of giant Chara corallina cells was investigated. The voltage–clamp technique was used to study Ca 2+ and Cl − transient currents in the plasmalemma of intact cells. The action of the complex and OA on the target cell membrane has a dose-dependent character. It was found that the La–OA complex has an inhibiting effect on Ca 2+ current across the plasmalemma, while α-lactalbumin alone does not affect the electrophysiological characteristics of the cellular membrane. However, oleic acid blocks Ca 2+ current across the plasmalemma. This is accompanied by the induction of a non-selective conductivity in the cellular membrane, a decrease in the resting potential and plasma membrane resistance of algal cells. We propose that the cytotoxicity of La–OA and other HAMLET-like complexes is determined by oleic acid acting as a blocker of potential-dependent Ca 2+ channels in the plasma membrane of target cells. The presented results show that the study model of green algae C. corallina cells plasmalemma is a convenient tool for the investigation of ion channels in many animal cells.