Effect of Ions on Agitation- and Temperature-Induced Aggregation Reactions of Antibodies
Effect of Ions on Agitation- and Temperature-Induced Aggregation Reactions of Antibodies
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DOI：
10.1007/s11095-008-9792-z
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发表时间：
2009-04-01
影响因子：
3.7
通讯作者：
Gokarn, Yatin R.
中科院分区：
文献类型：
--
作者：
Fesinmeyer, R. Matthew;Hogan, Sabine;Gokarn, Yatin R.
离子对蛋白质聚集的影响仍然知之甚少。我们探讨了离子强度和离子同一性在温度和搅拌诱导的抗体聚集中的作用，通过稳定性研究确定了单价Hofmeister阴离子和阳离子对三种IgG(2)单抗聚集倾向的影响。测定了mAbs的C(H)2区熔融温度(T(M1))和还原价态(z*)。在高温储存过程中，搅拌导致溶液浊度增加，形成了不溶性聚集体，同时形成了可溶性聚集体。聚集度随阴离子大小(F-<；Cl-<；Br-<；I-<；SCN-类似于ClO4(-))而增加，并与T(M1)和z*的降低相关。阴离子诱导的聚集倾向随阴离子的杂化性质而增加。阳离子的同一性(Li+、Na+、K+、Rb+或Cs+)对T(M1)、z*或搅拌时的聚集没有影响。结果表明，阴离子结合通过降低mAb的构象稳定性和价态来介导聚集。我们的观察支持一个搅拌诱导的粒子模型，在该模型中，阴离子促进了单抗在空气/水界面的分配和展开。聚集主要发生在这个界面上；在搅拌过程中表面的刷新将不溶的聚集体释放到整体溶液中。
The impact of ions on protein aggregation remains poorly understood. We explored the role of ionic strength and ion identity on the temperature- and agitation-induced aggregation of antibodies.Stability studies were used to determine the influence of monovalent Hofmeister anions and cations on aggregation propensity of three IgG(2) mAbs. The C(H)2 domain melting temperature (T (m1)) and reduced valence (z*) of the mAbs were measured.Agitation led to increased solution turbidity, consistent with the formation of insoluble aggregates, while soluble aggregates were formed during high temperature storage. The degree of aggregation increased with anion size (F- < Cl- < Br- < I- < SCN- similar to ClO4 (-)) and correlated with a decrease in T (m1) and z*. The aggregation propensity induced by the anions increased with the chaotropic nature of anion. The cation identity (Li+, Na+, K+, Rb+, or Cs+) had no effect on T (m1), z* or aggregation upon agitation.The results indicate that anion binding mediates aggregation by lowering mAb conformational stability and reduced valence. Our observations support an agitation-induced particulation model in which anions enhance the partitioning and unfolding of mAbs at the air/water interface. Aggregation predominantly occurs at this interface; refreshing of the surface during agitation releases the insoluble aggregates into bulk solution.