In vitro study on the interaction of Mn(II)-DiAmsar with human serum albumin (HSA) and bovine serum albumin (BSA) by spectroscopic and molecular docking methods

Abstract

Understanding the interaction between protein and manganese(II) Diamine sarcophagine (Mn(II)-DiAmsar) has significant implications for biological applications of Mn(II)-DiAmsar. To this aim, at first, Mn(II)-DiAmsar was synthesized and characterized. In the next step, the interaction between Mn(II)-DiAmsar and protein [human serum albumin (HSA) and bovine serum albumin (BSA)] was investigated by Fourier transform infrared (FT-IR), UV–Visible (UV–Vis), fluorescence spectroscopies, and cyclic voltammetry (CV) under the physiological conditions in Tris buffer solution adjusted to pH 7.4. FT-IR spectra revealed that the conformation and microenvironment of HSA and BSA were changed in the presence of Mn(II)-DiAmsar. Mn(II)-DiAmsar could strongly quench the intrinsic fluorescence of HSA and BSA by static quenching. The hydrogen bonding and weak van der Waals interaction plays a major role in stabilizing the Mn(II)-DiAmsar–HSA (BSA) complex. The binding site number n apparent binding constant Ka, and corresponding thermodynamic parameters ∆G°, ∆H° and ∆S° at different temperatures were calculated. The distance R between the donor (HSA and BSA) and acceptor (Mn(II)-DiAmsar) has been obtained utilizing fluorescence resonance energy transfer (FRET). Finally, the molecular docking was performed to explore the possible binding sites and assess the microenvironment around the bounded Mn(II)-DiAmsar with HSA and BSA. Our results clarified that Mn(II)-DiAmsar complex could bind to HSA and BSA effectively and could be a useful guideline for further biological applications.