How does cholinium cation surpass tetraethylammonium cation in amino acid-based ionic liquids for thermal and structural stability of serum albumins?
Sumit Kumar, Prasanna Kukutla, Nagaraju Devunuri, Pannuru Venkatesu
International Journal of Biological Macromolecules
In this study, we report how similarly two serum albumins (bovine serum albumin (BSA) and human serum albumin (HSA)) respond in the presence of different concentration of aromatic amino acid based ionic liquids (AAILs), which are cholinium tryptophan [CHO][Trp]IL and tetraethylammonium tryptophan [TEA][Trp]IL. Extended results of thermodynamic stability indicate the extent to which both serum albumins differ in their thermal stability despite having structural similarity in presence of AAILs. To efficiently quantify the results, biomolecular interactions studies were carried out between serum albumins and AAILs with the help of differential scanning calorimetry (DSC), dynamic light scattering (DLS) and various spectroscopic techniques. DSC results illustrated that both AAILs are increasing the thermal stability of BSA and HSA, as per transition temperature (Tm) values, BSA (65.51 to 72.46 °C) and HSA (65.46 to 75.97 °C) have more thermal stability in the presence of [CHO][Trp]IL as compare to [TEA][Trp]IL, BSA (65.51 to 69.75 °C) and HSA (65.46 to 72.08 °C). Secondary structure results obtained using Dichroweb software and selcon calculations. Furthermore, to illustrate the specific binding of AAIL's cations or anions with the binding sites of BSA and HSA, the molecular docking studies were also performed using Molegro trail version v 6.0.
Circular dichroism, Chemical stability, Secondary structure, Protein folding, Tertiary structure, Biochemistry