加热灭活病毒产生的低ACAIgG聚体的构象研究  

Study on Conformation of the low ACA IgG Aggregates Generated by Inactivation of Virus Using Pasterization Method

作　　者：姜永军[1] 蒋雪莲[1] 王憬惺[1] 

机构地区：[1]中国医学科学院中国协和医科大学输血研究所

出　　处：《中国输血杂志》2000年第3期149-152,共4页Chinese Journal of Blood Transfusion

摘　　要：目的 :探讨IVIG在 6 0℃、10h灭活病毒过程中 ,木糖醇和低 pH对于生成低ACAIgG聚体的作用。 方法 :利用高压液相、荧光光谱、圆二色谱、紫外吸收光谱以及IgG聚体对木瓜酶水解敏感性的差别来确定IgG聚体的空间构象及维持IgG聚体的价键变化。结果 :木糖醇及低pH的条件下加热导致IgG折叠趋于紧密 ,维持IgG聚体的价键增多 ,热稳定性增强 ,但其聚体的补体结合位点不易被C1大分子靠近亲和。相反 ,在无稳定剂存在时 ,6 3℃、2 0min、pH7.4的条件下加热导致IgG折叠趋于松散 ,其补体结合位点有利于C1大分子靠近亲和 ,相应的聚体激活补体的能力较强。结论 :IVIG在加热灭活病毒中 ,木糖醇和低 pH极大地降低了IgG聚体的生成及其ACA ,适宜的稳定剂和 pH的选择是制备高质量IVIG制品的重要环节。Objective:To inquire into the role played by xylitol and low pH in generation of IgG aggregates with low anticomplementary activity (ACA)during the inactivation of virus in IVIG by heating at 60℃ for 10 hours.Methods: The change of IgG aggregates spatial conformation and the change of valence bonds number responsible for keeping the IgG aggregates conformation were determined using the following methods:the high pressure liquid chromatography (HPLC), fluorescence spectrum,circular dichroism spectrum,ultraviolet absorption spectrum as well as the difference in susceptivity of IgG aggregates to papain hydrolysis.Results: It was showed that in the presence of xylitol and low pH,the heating could cause the IgG to be folded,tending to assume a compact conformation and so leading to the increase of valence bonds number responsible for keeping the IgG aggregates conformation,and subsequently to the improvement of IgG thermal stability,but the C1q binding site of IgG aggregates had no easy access and affinity for the macromolecules of C1q. On the contrary, the heating at 63℃ and pH7.4 for 20 minutes without stabilizer could cause the IgG aggregates to be folded,tending to assume a loosen conformation,and the C1q binding site of IgG aggregates became beneficial to access and affinity for macromolecules of C1q,and so the capability of IgG aggregates to activate the complements was more enhanced.Conclusion:During the inactivation of virus in IVIG by pasterization method,the xylitol and low pH reduces the production of IgG aggregates and their ACA greatly. The choice of suitable stabilizer and pH is a key link in preparation chain of high quality IVIG product.

关 键 词：静脉注射免疫球蛋白 聚体 灭活病毒 抗补体活性 

分 类 号：Q512.2[生物学—生物化学] R979.5[医药卫生—药品]