Study on the interaction of paeoniflorin with human serum albumin (HSA) by spectroscopic and molecular docking techniques

摘要

The interaction of paeoniflorin with human serum albumin (HSA) was investigated using fluorescence, UV鈥搗is 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 (螖H掳 = 鈭?nbsp;9.98 kJ mol鈭?, 螖S掳 = 28.18 J mol鈭? K鈭?). The binding constant was calculated to be 1.909 脳 103 L mol鈭? 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.