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

Abstract

To assess the toxicity of residual marbofloxacin from animal-derived food, the interaction characteristics of marbofloxacin to bovine/human serum albumins (BSA/HSA) were explored using spectroscopic methods combined with molecular modelling.According to fluorescence spectra and time-resolved fluorescence spectra measurements, quenching of BSA/HSA fluorescence induced by marbofloxacin was characterized as static quenching. A 1:1 ground-state complex of marbofloxacin to BSA/HSA was formed with binding constant (K a ) 1.66 × 10 4 /9.74 × 10 3 M −1 at 291 K. The location of marbofloxacin binding at site I within BSA/HSA was clarified by site marker competitive experiments. Molecular modelling demonstrated that the binding region for marbofloxacin to BSA and HSA were at site I with the lowest binding free energies of −22.86 and −21.60 kJ mol −1 , respectively. Hydrogen bonds and van der Waals forces were dominantly involved in the spontaneous binding. Nonradiation energy transferred from BSA and HSA to marbofloxacin, due to the close distance (r 0 ) between marbofloxacin and Trp residues of BSA (4.28 nm) and HSA (3.34 nm). As explained by circular dichroism (CD) spectra, an increased BSA/HSA α-helix structure was observed after binding to marbofloxacin. Ultraviolet-visible (UV-vis) and Fourier transform infrared (FT-IR) spectra suggested that conformation of the two proteins was altered by marbofloxacin.

Interaction mechanism of pelargonidin against tyrosinase by multi‐spectroscopy and molecular docking

“…ΔE 1 , ΔE 2 and ΔE 3 were obtained by molecular docking, and the results were listed in Table4. Thereby, H-bonds and vdW force were the main binding forces between tyrosinase and PG based on the ΔE 3 values were much lower than those ΔE 2 52. The docking results were consistent with those fluorescence assay.F I G U R E 8The CD spectra of tyrosinase-PG complex with the concentration ratios of 1:0, 1:1.7, 1:3.4 (molÁL À1 /molÁL À1 ) (a !…”

Interactions studies of CYP2D6 with quercetin and hyperoside by spectral analysis and molecular dynamics simulations

“…The values of ΔE 1 , ΔE 2 , and ΔE 3 are summarized in Table 5. Hydrogen bonds and van der Waals force are the main forces involved in the two bindings based on ΔE 3 being much lower than that of ΔE 2 , and these results are consistent with the fluorescence experiments [51].…”

Interactions between hydroxylated polycyclic aromatic hydrocarbons and serum albumins: multispectral and molecular docking analyses

“…[ 17 ] These structural variations cause significant differences in the pharmacological and biochemical properties of the two proteins. [ 18,19 ] Previous studies have revealed that the binding ability of HSA with ligands, such as drugs [ 17,20,21 ] and dyes, [ 22,23 ] is different to that of BSA. The binding of xenobiotic pollutants to functional biomacromolecules is considered as the origin of their toxic effects.…”