Interaction of new butyltin citrate complex with lipid model membrane and DNA

Organotin(IV) complexes show a wide variety of biological activity: bactericidal, fungicidal, caricidal, and pesticidal. Many of them are more effective than traditional heavy metal anticancer drugs. The aim of the present study was to investigate the interaction of a new dibutyltin complex with citric acid (DBTC) with lipid membrane and plasmid DNA. The effect of this compound on the multilamellar liposomes formed with dipalmitoylphosphatidylcholine, dimyristoylphosphatidylcholine, and dimyristoylphosphatidylethanolamine was studied mainly by the means of differential scanning calorimetry and additionally by the steady-state fluorimetry. Calorimetrical results together with fluorescence spectroscopy suggest that investigated complex interacts with lipids and probably locates itself in the hydrophilic part of the membrane. The effect of DBCT on plasmid DNA was investigated using single-molecule florescence technique and time-correlated single photon counting fluorescence correlation spectroscopy. We could conclude then that DBTC–DNA interaction occurs due to the interaction with the DNA phosphate group and charge neutralization which then leads to DNA compaction.