BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University, Gyeonggi 10326, Republic of Korea.
Department of Pharmacy, College of Pharmacy, Mokpo National University, Muan 58554, Republic of Korea.
Int J Pharm. 2023 Nov 25;647:123545. doi: 10.1016/j.ijpharm.2023.123545. Epub 2023 Oct 21.
Arginine and its derivatives (such as arginine ethyl ester and acetyl arginine) have varying degrees of protein aggregation suppressor effect across different protein solutions. To understand this performance ambiguity, we evaluated the activity of arginine, acetyl arginine, and arginine ethyl ester for aggregation suppressor effect against human intravenous immunoglobulin G (IgG) solution at pH 4.8. Both arginine and its cationic derivative arginine ethyl ester in their hydrochloride salt forms significantly reduced the colloidal and conformational stability (reduced k and T) of IgG. Consequently, the monomer content was decreased with an increase in subvisible particulates after agitation or thermal stress. Furthermore, compared to arginine, arginine ethyl ester with one more cationic charge and hydrochloride salt form readily precipitated IgG at temperatures higher than 25 °C. On the contrary, acetyl arginine, which mostly exists in a neutral state at pH 4.8, efficiently suppressed the formation of subvisible particles retaining a high amount of monomer owing to its higher colloidal and conformational stability. Concisely, the charged state of additives significantly impacts protein stability. This study demonstrated that contrary to popular belief, arginine and its derivatives may either enhance or suppress protein aggregation depending on their net charge and concentration.
精氨酸及其衍生物（如精氨酸乙酯和乙酰精氨酸）在不同的蛋白质溶液中对蛋白质聚集具有不同程度的抑制作用。为了了解这种性能的不明确性，我们评估了精氨酸、乙酰精氨酸和精氨酸乙酯在 pH4.8 时对人静脉注射免疫球蛋白 G（IgG）溶液的聚集抑制效果。盐酸精氨酸和盐酸精氨酸乙酯这两种带正电荷的衍生物形式都显著降低了 IgG 的胶体和构象稳定性（降低了 k 和 T）。因此，在搅拌或热应激后，单体含量减少，亚可见颗粒增加。此外，与精氨酸相比，带一个额外正电荷的盐酸盐形式的精氨酸乙酯在高于 25°C 的温度下更容易沉淀 IgG。相反，在 pH4.8 时主要呈中性状态的乙酰精氨酸由于其更高的胶体和构象稳定性，有效地抑制了亚可见颗粒的形成，保留了大量的单体。简而言之，添加剂的带电状态对蛋白质稳定性有显著影响。本研究表明，与普遍看法相反，精氨酸及其衍生物可能会增强或抑制蛋白质聚集，具体取决于它们的净电荷和浓度。
