成像毛细管等点聚焦电泳法对单克隆抗体制品的电荷异质性分析

Charge heterogeneity analysis of monoclonal antibody products with imaging capillary isoelectric focusing electrophoresis

目的:采用成像毛细管等点聚焦电泳法分析单克隆抗体制品的电荷异质性。方法:应用优化的成像毛细管等点聚焦电泳技术,对2种单克隆抗体制品酶切处理前后进行电荷异质性分析。结果:羧肽酶B处理前后的抗体1成像毛细管等点聚焦电泳结果比较证明其电荷异质性主要由C末端赖氨酸不均一性引起;羧肽酶B处理和/或N-糖苷酶处理前后的抗体2成像毛细管等点聚焦电泳结果比较证明其电荷异质性主要由C末端赖氨酸不均一性和N-糖的唾液酸修饰引起。结论:采用优化的成像毛细管等点聚焦电泳技术,可较好地分析单克隆抗体产品的电荷异质性;并且配合合适的酶切处理,可判断单克隆抗体产品主要电荷异质性的来源,为保证单克隆抗体产品技术药物生产工艺的稳定性及质量控制提供了有效手段。

Objective： To investigate the charge heterogeneity of monoclonal antibody products with imaging capillary isoelectric focusing electrophoresis（ iCIEF）. Methods： With the optimized iCIEF,the charge heterogeneity of two monoclonal antibody products was analyzed before and after enzyme treatments. Results： The iCIEF results before and after CpB enzymatic treatment showed that the charge heterogeneity of antibody 1 was mainly caused by heterogeneity of C- terminal lysine; the iCIEF results before and after CpB and /or PNGase enzymatic treatments proved that the charge heterogeneity of antibody 2 was caused by heterogeneity of C- terminal lysine and sialic acid modification at N- glycan terminus. Conclusion： With the optimized technique of imaging capillary isoelectric focusing electrophoresis,the charge heterogeneity of monoclonal antibody products could be well analyzed. While in combination with appropriate enzymatic treatments,the main origin of heterogeneity could be determined. The technique provides an effective tool for ensuring the stability of production procedure and quality control of monoclonal antibody products.