Wen Lili, Zheng Xianxian, Wang Xinyue, Lan Hairong, Yin Zongning
Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, No. 17, Block 3 Southern Renmin Road, Chengdu, Sichuan Province, 610041, People's Republic of China.
Pharm Res. 2017 Jul;34(7):1378-1390. doi: 10.1007/s11095-017-2152-0. Epub 2017 Apr 11.
Understanding the mechanism of protein-excipient interaction and illuminating the influencing factors on protein stability are key steps in the rational design of protein formulations. The objective of this study was to assess effects of preferential interaction type of excipient and surface aromatic hydrophobicity of protein on protein solution stability.
The preferential interaction between excipient and aromatic hydrophobic area of protein was investigated by solubility and fluorescence studies of amino acid derivatives in excipient solutions. We examined conformational, colloidal and mechanical stabilities of model proteins with different surface aromatic hydrophobicities, including bovine serum albumin (BSA) and ovalbumin (OVA), and then stability data were visualized by three-index empirical phase diagram.
The result showed that preferentially excluded excipients (trehalose, sucrose and sorbitol) protected protein conformation against damage, but they could accelerate mechanical stress-induced aggregation. Preferentially bound excipients (propanediol and arginine) suppressed BSA aggregation, but arginine failed to inhibit OVA aggregation, which might be attributed to the disparate conformational perturbing effects of arginine on aromatic hydrophobic regions of BSA and OVA.
These findings provided strong evidence that excipient possessed bilateral effects, and its application should be determined on different preferential interaction behaviors of excipients with protein, especially with the aromatic hydrophobic region.
了解蛋白质与辅料相互作用的机制并阐明影响蛋白质稳定性的因素是合理设计蛋白质制剂的关键步骤。本研究的目的是评估辅料的优先相互作用类型和蛋白质表面芳香族疏水性对蛋白质溶液稳定性的影响。
通过氨基酸衍生物在辅料溶液中的溶解度和荧光研究，考察辅料与蛋白质芳香族疏水区域之间的优先相互作用。我们检测了具有不同表面芳香族疏水性的模型蛋白（包括牛血清白蛋白（BSA）和卵清蛋白（OVA））的构象、胶体和机械稳定性，然后通过三指标经验相图直观呈现稳定性数据。
结果表明，优先被排斥的辅料（海藻糖、蔗糖和山梨醇）可保护蛋白质构象免受破坏，但会加速机械应力诱导的聚集。优先结合的辅料（丙二醇和精氨酸）可抑制BSA聚集，但精氨酸无法抑制OVA聚集，这可能归因于精氨酸对BSA和OVA芳香族疏水区域的构象扰动作用不同。
这些发现提供了有力证据，表明辅料具有双重作用，其应用应根据辅料与蛋白质，尤其是与芳香族疏水区域的不同优先相互作用行为来确定。
