Quinoline yellow (QY) is a synthetic yellow dye widely used as a coloring agent for various foodstuffs. In the current study, we have examined the role of QY on the aggregation propensity of hen egg-white lysozyme (HEWL) under physiological conditions. The dye induced conformational changes in HEWL leading to aggregate formation were identified by circular dichroism (CD), turbidity analysis, fluorescence measurement and microscopic (TEM) imaging. Molecular docking and molecular dynamics simulation studies were also employed to strengthen binding and aggregation results. Our results indicate that 25–100 µM of QY induces aggregation in HEWL, while lower QY concentrations (5 and 10 µM) does not have any effect on the aggregation propensity of HEWL. The kinetics of HEWL aggregation demonstrate nucleation independent aggregation of HEWL without lag phase. On the other hand, far UV-CD analysis illustrated the loss of α-helical structure with the increasing concentration of QY. TEM results also support the formation of aggregate structures in HEWL when exposed to QY. Molecular docking and simulation studies revealed that the HEWL-QY complex is stable as compared to individual entities. In silico analysis also illustrated that QY-induced aggregation of HEWL proceeds through the formation of hydrogen bonds, electrostatic (Pi-Anion) and Pi-Sulfur interactions. The above-mentioned results highlight the possible detrimental effect by food additive dyes, particularly in protein misfolding.

喹啉黄（QY）是一种合成的黄色染料，广泛用作各种食品的着色剂。在当前的研究中，我们已经研究了QY在生理条件下对蛋清溶菌酶（HEWL）聚集倾向的作用。通过圆二色性（CD），浊度分析，荧光测量和显微（TEM）成像鉴定了染料诱导的HEWL构象变化（导致聚集体形成）。分子对接和分子动力学模拟研究也被用来加强结合和聚集结果。我们的结果表明，25–100 µM的QY诱导HEWL聚集，而较低的QY浓度（5和10 µM）对HEWL的聚集倾向没有任何影响。HEWL聚集的动力学表明HEWL的成核独立聚集而没有滞后相。另一方面，远紫外-CD分析表明随着QY浓度的增加，α-螺旋结构的损失。TEM结果还支持暴露于QY时HEWL中聚集体结构的形成。分子对接和模拟研究表明，与单个实体相比，HEWL-QY复合物是稳定的。在计算机分析中还表明，QY诱导的HEWL聚集通过形成氢键，静电（Pi-阴离子）和Pi-硫相互作用而进行。上述结果突出了食品添加剂染料的可能有害作用，特别是在蛋白质错误折叠中。远UV-CD分析表明随着QY浓度的增加α-螺旋结构的损失。TEM结果还支持暴露于QY时HEWL中聚集体结构的形成。分子对接和模拟研究表明，与单个实体相比，HEWL-QY复合物是稳定的。在计算机分析中还表明，QY诱导的HEWL聚集通过形成氢键，静电（Pi-阴离子）和Pi-硫相互作用而进行。上述结果突出了食品添加剂染料的可能有害作用，特别是在蛋白质错误折叠中。远UV-CD分析表明随着QY浓度的增加α-螺旋结构的损失。TEM结果还支持暴露于QY时HEWL中聚集体结构的形成。分子对接和模拟研究表明，与单个实体相比，HEWL-QY复合物是稳定的。在计算机分析中还表明，QY诱导的HEWL聚集通过形成氢键，静电（Pi-阴离子）和Pi-硫相互作用而进行。上述结果突出了食品添加剂染料的可能有害作用，特别是在蛋白质错误折叠中。在计算机分析中还表明，QY诱导的HEWL聚集通过形成氢键，静电（Pi-阴离子）和Pi-硫相互作用而进行。上述结果突出了食品添加剂染料的可能有害作用，特别是在蛋白质错误折叠中。在计算机分析中还表明，QY诱导的HEWL聚集通过形成氢键，静电（Pi-阴离子）和Pi-硫相互作用而进行。上述结果突出了食品添加剂染料的可能有害作用，特别是在蛋白质错误折叠中。