Inhibition of Na(+)/K(+)-ATPase and cytotoxicity of a few selected gold(III) complexes.
J Inorg Biochem 2014;
140:228-35. [PMID:
25173578 DOI:
10.1016/j.jinorgbio.2014.07.015]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/16/2014] [Accepted: 07/16/2014] [Indexed: 12/24/2022]
Abstract
Na(+)/K(+)-ATPase is in charge of maintaining the ionic and osmotic intracellular balance by using ATP as an energy source to drive excess Na(+) ions out of the cell in exchange for K(+) ions. We explored whether three representative cytotoxic gold(III) compounds might interfere with Na(+)/K(+)-ATPase and cause its inhibition at pharmacologically relevant concentrations. The tested complexes were [Au(bipy)(OH)2][PF6] (bipy=2,2'-bipyridine), [Au(py(dmb)-H)(CH3COO)2] (py(dmb)-H=deprotonated 6-(1,1-dimethylbenzyl)-pyridine), and [Au(bipy(dmb)-H)(OH)][PF6] (bipy(dmb)-H=deprotonated 6-(1,1-dimethylbenzyl)-2,2'-bipyridine). We found that all of them caused a pronounced and similar inhibition of Na(+)/K(+)-ATPase activity. Inhibition was found to be non-competitive and reversible. Remarkably, treatment with cysteine resulted in reversal or prevention of Na(+)/K(+)-ATPase inhibition. It is very likely that the described effects may contribute to the overall cytotoxic profile of these gold complexes.
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