Abstract
The interaction of paeoniflorin with human serum albumin (HSA) was investigated using fluorescence, UV–vis absorption, circular dichroism (CD) spectra and molecular docking techniques under simulative physiological conditions. The results clarified that the fluorescence quenching of HSA by paeoniflorin was a static quenching process and energy transfer as a result of a newly formed complex (1:1). Paeoniflorin spontaneously bound to HSA in site I (subdomain IIA), which was primarily driven by hydrophobic forces and hydrogen bonds (ΔH° = − 9.98 kJ mol−1, ΔS° = 28.18 J mol−1 K−1). The binding constant was calculated to be 1.909 × 103 L mol−1 at 288 K and it decreased with the increase of the temperature. The binding distance was estimated to be 1.74 nm at 288 K, showing the occurrence of fluorescence energy transfer. The results of CD and three-dimensional fluorescence spectra showed that paeoniflorin induced the conformational changes of HSA. Meanwhile, the study of molecular docking also indicated that paeoniflorin could bind to the site I of HSA mainly by hydrophobic and hydrogen bond interactions.
Highlights
Radix Paeoniae Rubra (RPR), the dried root of Paeonia lactiflora Pall or Paeonia veitchii Lynch, has been widely used by Chinese medicine practitioners to treat cardiovascular, inflammation and female reproductive diseases [1]
In this paper, the interaction of paeoniflorin with human serum albumin (HSA) was investigated by fluorescence, UV–vis, circular dichroism (CD) and molecular docking techniques under simulated physiological conditions
The results demonstrated that the fluorescence of HSA would be quenched with the addition of paeoniflorin
Summary
Radix Paeoniae Rubra (RPR), the dried root of Paeonia lactiflora Pall or Paeonia veitchii Lynch, has been widely used by Chinese medicine practitioners to treat cardiovascular, inflammation and female reproductive diseases [1]. Human serum albumin (HSA) is the most studied serum albumin because its primary structure is well known and it can interact with many endogenous and exogenous substances [8]. It is a single-chain, non-glycosylated globular protein consisting of 585 amino acid residues, and 17 disulfide bridges assist in maintaining its familiar heartlike shape [9]. The principal regions of ligand binding sites in HSA are located in hydrophobic cavities in subdomains IIA and IIIA, called site I and site II, respectively [10] These multiple binding sites underline the exceptional ability of HSA to act as a major depot and transport protein which is capable
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
