The interaction of cholinium-based ionic liquids with different biological origin anions with albumins

Abstract

The intermolecular interactions of cholinium-based ionic liquids (ILs) with biological origin anions (amino and dicarboxylic acids) with bovine serum albumin (BSA) and human serum albumin (HSA) have been studied by spectral and computational methods. The choline malonate ([Ch][Mal]), choline succinate ([Ch][Suc]) and choline valinate ([Ch][Val]) were synthesized. The changes to the state of the BSA and HSA with ILs at different concentration were observed using circular dichroism (CD) spectroscopy. At higher concentrations the ILs lead to a partial loss of ternary structure of albumins. The effect of ILs on the thermal stability of proteins was monitored by the temperature CD spectra scans. The increase of denaturation temperature of albumins with ionic liquids was observed. The interaction of ionic liquids with serum albumins was estimated by fluorescence spectroscopy technique, while the probable binding modes were identified using molecular docking. The leading cause of the increased thermal stability of albumins was found to be the formation of aggregates of proteins with ionic liquids. Cytotoxicity of ionic liquids on cancer and normal cell lines was established.