College of Chemical Engineering, Sichuan University, Chengdu 610065, China.
College of Chemical Engineering, Sichuan University, Chengdu 610065, China.
Food Chem. 2017 Oct 15;233:190-196. doi: 10.1016/j.foodchem.2017.04.119. Epub 2017 Apr 20.
Thiabendazole (TBZ), which is oxidized into 5-hydroxythiabendazole (5-OH-TBZ) in vivo, is a commonly used food preservative. Interactions of TBZ and 5-OH-TBZ with human serum albumin (HSA) were comprehensively studied via multiple spectroscopic methods and molecular docking. This study focussed on the mechanistic and structural information on binding of TBZ and 5-OH-TBZ to HSA to evaluate the impact of the food additive on HSA. H NMR spectra of the two ligands showed the binding exists. ITC and fluorescence spectroscopy results revealed that TBZ was a stronger ligand, with a binding constant of 10l/mol and formed a more stable complex with HSA than did 5-OH-TBZ via electrostatic interaction. Spectroscopic results (UV-vis, FT-IR, and CD) showed that TBZ and 5-OH-TBZ caused conformational changes in HSA, in which α-helix and β-turn transformed into β-sheet, causing HSA structure to loosen. Docking programs showed that both TBZ and 5-OH-TBZ bound to HSA via IB.
噻苯达唑（TBZ）在体内氧化为 5-羟噻苯达唑（5-OH-TBZ），是一种常用的食品防腐剂。本研究采用多种光谱方法和分子对接技术，全面研究了 TBZ 和 5-OH-TBZ 与人血清白蛋白（HSA）的相互作用。该研究重点关注 TBZ 和 5-OH-TBZ 与 HSA 结合的机制和结构信息，以评估食品添加剂对 HSA 的影响。两种配体的 NMR 图谱表明结合存在。ITC 和荧光光谱结果表明，TBZ 是一种更强的配体，与 HSA 形成更稳定的复合物，结合常数为 10l/mol，通过静电相互作用与 5-OH-TBZ 相比。光谱结果（UV-vis、FT-IR 和 CD）表明，TBZ 和 5-OH-TBZ 引起 HSA 的构象变化，其中α-螺旋和β-转角转变为β-折叠，导致 HSA 结构松弛。对接程序表明，TBZ 和 5-OH-TBZ 均通过 IB 与 HSA 结合。
