Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia.
Protein Research Chair, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
Int J Biol Macromol. 2019 Apr 15;127:297-305. doi: 10.1016/j.ijbiomac.2019.01.049. Epub 2019 Jan 14.
Allura red (AR) is an artificial azo dye mostly used in food industries and has potential health risks. We examined the role of AR in amyloidogenesis using hen egg white lysozyme (HEWL) at pH 7.0. The amyloidogenic induction properties of AR in HEWL were identified by circular dichroism (CD), turbidity, intrinsic fluorescence, light scattering, transmission electron microscopy (TEM), and molecular dynamic simulation studies. Turbidity and light scattering measurements showed that HEWL becomes aggregated in the presence of 0.03-15.0 mM of AR at pH 7.0 but not at very low AR concentrations (0.01-0.28 mM). However, AR-induced aggregation is a kinetically rapid process, with no observable lag phase and saturation within 6 s. The kinetics results suggested that the HEWL aggregation induced by AR is very rapid. The CD results demonstrated that the total β-sheet content of HEWL was increased in the AR treated samples. The TEM results are established that AR-induced aggregates had amyloid-like structures. Molecular dynamics simulations analysis showed that the bound AR-HEWL structures were highly favored compared to unbound structures. The mechanism of AR-induced amyloid fibril formation may involve electrostatic, hydrogen bonding, and hydrophobic interactions.
诱惑红（AR）是一种人工偶氮染料，主要用于食品工业，具有潜在的健康风险。我们在 pH 值为 7.0 时使用鸡卵清白溶菌酶（HEWL）研究了 AR 在淀粉样蛋白形成中的作用。通过圆二色性（CD）、浊度、本征荧光、光散射、透射电子显微镜（TEM）和分子动力学模拟研究确定了 AR 在 HEWL 中诱导淀粉样蛋白形成的特性。浊度和光散射测量表明，在 pH 值为 7.0 时，HEWL 在 0.03-15.0 mM 的 AR 存在下发生聚集，但在非常低的 AR 浓度（0.01-0.28 mM）下则不会发生聚集。然而，AR 诱导的聚集是一个快速的动力学过程，在 6 s 内没有可观察到的滞后期和饱和期。动力学结果表明，AR 诱导的 HEWL 聚集非常迅速。CD 结果表明，AR 处理样品中 HEWL 的总 β-折叠含量增加。TEM 结果表明，AR 诱导的聚集具有类似淀粉样的结构。分子动力学模拟分析表明，与未结合结构相比，结合的 AR-HEWL 结构更有利。AR 诱导的淀粉样纤维形成的机制可能涉及静电、氢键和疏水相互作用。
