Astaxanthin Binding Affinity to DNA: Studied By Fluorescence, Surface Plasmon Resonance and Molecular Docking Methods

Abstract

Astaxanthin (Ax), as a novel food supplement, a pink-red pigment, belongs to the carotenoid family. The study of DNA interactions with various drugs is very important for estimating the mechanism of interaction and developing new drugs. The purpose of this study is to investigate the binding a nity of Ax to double strand (ds) DNA evaluated by using a uorescence spectroscopy, surface plasmon resonance (SPR) and docking approaches. The uorescence results shown that Ax can quench the intensity amount of DNA uorescence via a static quenching way. In the SPR method, DNA molecules were attached on a gold sensor surface. Using different amounts of ds DNA, the kinetic values K D , K A , and K a were calculated. The obtained nding con rm that the binding of Ax to DNA has an exothermic and spontaneous mechanism. Also, thermodynamic studies were carried out using uorescence analysis at four different temperatures, and the resulted negative data for ΔH and ΔS displayed that the main binding strength in the interaction of Ax to DNA was hydrogen bonding. Molecular docking results con rmed that the side chains of Ax interact speci cally with base pairs and the DNA backbone. HighlightsThe binding strength of astaxanthin (Ax) to double strands (ds) DNA was investigated.The uorescence results shown that Ax can quench the DNA.The obtained negative values for ΔH and ΔS indicated that the binding of Ax to DNA was spontaneous process.Major binding force involved in intercalation of AX to DNA was hydrogen bonding.Molecular docking results con rmed that the side chains of Ax interact with DNA.