Exploration of interaction of canthaxanthin with human serum albumin by spectroscopic and molecular simulation methods

Abstract

The interaction between the food colorant canthaxanthin (CA) and human serum albumin (HSA) in aqueous solution was explored by using fluorescence spectroscopy, three-dimensional fluorescence spectra, synchronous fluorescence spectra, UV-vis absorbance spectroscopy, circular dichroism (CD) spectra and molecular docking methods. The thermodynamic parameters calculated from fluorescence spectra data showed that CA could result in the HSA fluorescence quenching. From the K change with the temperature dependence, it was concluded that HSA fluorescence quenching triggered by CA is the static quenching and the number of binding sites is one. Furthermore, the secondary structure of HSA was changed with the addition of CA based on the results of synchronous fluorescence, three-dimensional fluorescence and CD spectra. Hydrogen bonds and van der Waals forces played key roles in the binding process of CA with HSA, which can be obtained from negative standard enthalpy (ΔH) and negative standard entropy (ΔS). Furthermore, the conclusions were certified by molecular docking studies and the binding mode was further analyzed with Discovery Studio. These conclusions can highlight the potential of the interaction mechanism of food additives and HSA.

Interactions of Bromocarbazoles with Human Serum Albumin Using Spectroscopic Methods

“…According to Ross’s theory, the positive signs of the ΔH and ΔS values indicated that 3-bromocarbazole bound to HSA depending on typical hydrophobic forces with endothermic performance, and the negative signs of ΔH and positive signs of ΔS for 1,3,6,8-tetrabromocarbazole interacted with HSA, driven by electrostatic interactions and hydrophobic forces with exothermic performance. Both are spontaneous processes [33,35].…”

Probing the interaction of l‐captopril with metallo‐β‐lactamase CcrA by fluorescence spectra and molecular dynamic simulation

“…UV–vis absorption spectra can be used to explore the CcrA structural change and complex formation . The UV–vis absorption spectra of CcrA in the absence or presence of Lcap are shown in Figure .…”