Mechanism of Na+/K+-Atpase and Mg2+-Atpase Inhibition By Metal Ions and Complexes

Abstract

The aim of the study was to give an overview of the mechanism of inhibition of Na+/K+-ATPase and Mg2+-ATPase activity, the enzymes playing a key role in the active transport of monovalent cations (Na+ and K+) across the cell membrane, induced by the ions of some transition (Cu2+, Zn2+, Fe2+, Co2+) and heavy (Hg2+ i Cd2+) metals, ammonium decavanadate and noble metals complexes ([PtCl2DMSO2], [AuCl4](-), [PdCl4](2-), [PdCl(dien)](+), [PdCl(Me(4)dien)](+)). The extensive kinetic analysis was done in order to determine kinetic parameters and the mode of interaction of Na+/K+-ATPase and Mg2+-ATPase and the investigated compounds. In addition, the ability of sulphur-donor ligands (L-cysteine and glulathione), as well as EDTA, to prevent metal ions and complexes induced inhibition of Na+/K+-ATPase activity and to recover enzymatic activity was investigated Finally, development of highly sensitive and selective analytical tools on the basis of the immobilized enzyme is discussed in this paper.

U ovom radu je dat pregled mehanizma interakcije Na+/K+–ATPaze i Mg2+–ATPaze, enzima koji igraju ključnu ulogu u aktivnom transportu katjona kroz ćelijsku membranu, i jona prelaznih metala (Cu2+, Zn2+, Fe2+ i Co2+), jona teških metala (Hg2+ i Cd2+), amonijum-dekavanadata i kompleksa plemenitih metala ([PtCl2DMSO2], [AuCl4]–, [PdCl4]2–, [PdCl(dien)]+, [PdCl(Me4dien)]+). Kinetička analiza je urađena u cilju određivanja kinetičkih parametara i tipa inhibicije enzima ovim jedinjenjima. Takođe je ispitivana sposobnost L-cisteina i glutationa (koji sadrže sumpor) da spreče inhibiciju Na+/K+–ATPaze matalnim jonima i kompleksima plemenitih metala i reaktiviraju aktivnost inhibiranog enzima. Na kraju, razvoj osetljivih i selektivnih analitičkih oruđa na bazi imobilizovane Na+/K+––ATPaze je razmotren.