A型肉毒抗毒素的层析纯化

Purification of group A botulinum antitoxin by chromatography

目的层析纯化A型肉毒抗毒素,提高免疫球蛋白F（ab′）2的纯度。方法采用阴离子交换层析纯化A型肉毒抗毒素,并通过试验设计（design of experiment,DoE）方法优化缓冲液的pH与电导。结果流穿液中的小分子杂蛋白含量受电导的影响较显著,并随着电导的降低而降低,而pH在试验设计范围内对其影响较小;聚集体/聚合体含量在低pH、高电导时含量较高,高pH、低电导时含量较低;F（ab′）2的纯度主要受电导的影响,并随着电导的升高而降低,在试验设计范围（2-20 ms/cm）内,F（ab′）2的纯度均在90%以上。结论采用阴离子交换层析可有效降低A型肉毒抗毒素中聚集体/聚合体以及部分小分子杂蛋白的含量,提高F（ab′）2的含量。

Objective To purify group A botulinum antitoxin by chromatography so as to increase the purity of immunoglobulin F（ab′）2. Methods Group A botulinum antitoxin was purified by anion-exchange chromatography. The pH value and conductivity of buffer were optimized by Design of Experiments（DoE）. Results The low molecular impurity content in flow through buffer was influenced significantly by conductivity, which decreased with the decreasing conductivity. However,pH value with the range of DoE showed little effect on the content. The aggregate / polymer content was high at low pH values and high conductivity,while was low at high pH values and low conductivity. The purity of F（ab′）2was mainly influenced by conductivity,which decreased with the increasing conductivity,and was more than 90% when the conductivity was within the DoE range（2 - 20 ms / cm）. Conclusion Anion-exchange chromatography decreased the aggregate / polymer and partial low molecular impurity contents in group A botulinum antitoxin and increased the purity of F（ab′）2.