Thimerosal has been widely used as a preservative in drug and vaccine products for decades. Due to the strong propensity to modify thiols in proteins, conformational changes could occur due to covalent bond formation between ethylmercury (a degradant of thimerosal) and thiols. Such a conformational change could lead to partial or even complete loss of desirable protein function. This study aims to investigate the effects of thimerosal on the capsid stability and antigenicity of recombinant human papillomavirus (HPV) 18 virus-like particles (VLPs). Dramatic destabilization of the recombinant viral capsid upon thimerosal treatment was observed. Such a negative effect on the thermal stability of VLPs preserved with thimerosal was shown to be dependent on the thimerosal concentration. Two highly neutralizing antibodies, 13H12 and 3C3, were found to be the most sensitive to thimerosal treatment. The kinetics of antigenicity loss, when monitored with 13H12 or 3C3 as probes, yielded two distinctly different sets of kinetic parameters, while the data from both monoclonal antibodies (mAbs) followed a biphasic exponential decay model. The potential effect of thimerosal on protein function, particularly for thiol-containing proteinaceous active components, needs to be comprehensively characterized during formulation development when a preservative is necessary.

几十年来，硫柳汞已被广泛用作药物和疫苗产品的防腐剂。由于修饰蛋白质中硫醇的强烈倾向，由于乙基汞（硫柳汞的降解物）和硫醇之间形成共价键，可能会发生构象变化。这种构象变化可能导致所需蛋白质功能的部分甚至完全丧失。本研究旨在研究硫柳汞对重组人乳头瘤病毒 (HPV) 18 病毒样颗粒 (VLP) 衣壳稳定性和抗原性的影响。观察到在硫柳汞处理后重组病毒衣壳的显着不稳定。这种对用硫柳汞保存的 VLP 的热稳定性的负面影响被证明取决于硫柳汞的浓度。两种高度中和的抗体，13H12 和 3C3，发现对硫柳汞处理最敏感。当用 13H12 或 3C3 作为探针监测时，抗原性丧失的动力学产生两组截然不同的动力学参数，而来自两种单克隆抗体 (mAb) 的数据遵循双相指数衰减模型。硫柳汞对蛋白质功能的潜在影响，特别是对于含硫醇的蛋白质活性成分，需要在需要防腐剂的配方开发过程中进行全面表征。