Exploring the interactions of a Tb(III)–quercetin complex with serum albumins (HSA and BSA): spectroscopic and molecular docking studies

Abstract

Serum albumins (human serum albumin (HSA) and bovine serum albumin (BSA), two main circulatory proteins), are globular and monomeric macromolecules in plasma that transport many drugs and compounds. In the present study, we investigated the interactions of the Tb(III)-quercetin (Tb-QUE) complex with HSA and BSA using common spectroscopic techniques and a molecular docking study. Fluorescence data revealed that the inherent fluorescence emission of HSA and BSA was markedly quenched by the Tb-QUE complex through a static quenching mechanism, confirming stable complex formation (a ground-state association) between albumins and Tb-QUE. Binding and thermodynamic parameters were obtained from the fluorescence spectra and the related equations at different temperatures under biological conditions. The binding constants (K b ) were calculated to be 0.8547 × 10 3 M −1 for HSA and 0.1363 × 10 3 M −1 for BSA at 298 K. Also, the number of binding sites (n) of the HSA/BSA-Tb-QUE systems was obtained to be approximately 1. Thermodynamic data calculations along with molecular docking results indicated that electrostatic interactions have a main role in the binding process of the Tb-QUE complex with HSA/BSA. Furthermore, molecular docking outputs revealed that the Tb-QUE complex has high affinity to bind to subdomain IIA of HSA and BSA. Binding distances (r) between HSA-Tb-QUE and BSA-Tb-QUE systems were also calculated using the Forster (fluorescence resonance energy transfer) method. It is expected that this study will provide a pathway for designing new compounds with multiple beneficial effects on human health from the phenolic compounds family such as the Tb-QUE complex. K E Y W O R D SFluorescence quenching, molecular docking, serum albumins, spectroscopic technique, Tb(III)quercetin complex

Assessment on the binding characteristics of residual marbofloxacin in animal‐derived food to bovine/human serum albumin by spectroscopy and molecular modelling

“…[8][9][10] Some researchers have studied the molecular binding nature of drugs with biomacromolecules using different spectroscopic techniques. [11][12][13][14][15][16] However, to date, the binding characteristics of marbofloxacin to BSA/HSA are still unknown. Here, various characteristics of BSA/HSA caused by marbofloxacin binding including fluorescence quenching mechanisms, binding constant, binding site, binding force, binding distance, and conformational variations were determined and could provide a theoretical foundation for choosing moderate medication dosages when treating animal diseases.…”

Interaction study of astilbin, isoastilbin and neoastilbin toward CYP2D6 by multi‐spectroscopy and molecular docking

“…The non‐covalent interactions between ligands and macromolecules can result from hydrophobic and hydrogen bonding, electrostatic and van der Waals forces. [ 32 ] The values of Δ H 0 and Δ S 0 are conducive to determining the binding forces. [ 33 ] The Δ H 0 , Δ S 0 and Δ G 0 values are listed in Table 1.…”

A rapid, simple and ultrasensitive spectrofluorimetric method for the direct detection of metformin in real samples based on a nanoquenching approach

“…Further analysis of fluorescence quenching data was carried out using the Stern–Volmer equation (Eqn 3) [ 33,38,63,65 ] : where F 0 and F represent the emission intensity of the complex without or with the quencher (AgNPs), respectively. K sv and [Q] are the Stern–Volmer quenching constant and total concentration of quencher (AgNPs), respectively.…”