LAUSR

Abstract The binding mechanism and stability study of triprolidine hydrochloride (TRP), a H1-receptor antagonist with model transport protein, bovine serum albumin (BSA) has been investigated using isothermal titration calorimetry (ITC), enzyme kinetics, chemical and thermal denaturation along with molecular docking method. The association constant (Ka), standard enthalpy change (ΔH°), standard entropy change (ΔS°) and standard Gibbs free energy change (ΔG°) were obtained from ITC which suggest that the interaction of BSA with TRP is an endothermic process and hydrophobic forces play a major role in complexation. The effect of TRP on chemical and thermal denaturantion of BSA has been shown by CD spectroscopy substantiating that the stability of unfolded state is enhanced due by TRP. The esterase-like activity of BSA in presence of TRP shows that it inhibits the esterase activity of BSA in a competitive manner. Molecular docking was performed to further confirm the binding forces responsible for the complex formation and amino acids involved in this process. Thus, this study will provide useful information regarding the interaction of TRP with BSA, helping to understand the activity, stability and mechanism of TRP binding and highlights its importance in the clinical medicine.