中文摘要：

通过不同修饰反应物质的量比、修饰反应时间、pH值,用单甲氧基聚乙二醇琥珀酰亚胺酯（SC-mPEG）对牛乳β-乳球蛋白（β-LG）进行修饰,研究其抗原性的变化。利用间接竞争ELISA检测结合产物的抗原性,结果显示不同条件下PEG修饰后的β-乳球蛋白的抗原性最高降低率,反应8h时为70.2%。三硝基苯磺酸（TNBS）法测定不同条件反应后样品修饰度,反应8h时最高修饰度为39.1%。结果表明修饰反应时间为SC-mPEG修饰β-LG后其抗原性降低的主要因素。

英文摘要：

β-Lactoglobulin（β-LG） was modified by suecinimidyl carbonate methoxy polyethlene glycol（SC-mPEG） under different conditions of molar ratio,reaction time and pH.The change of its antigenicity was also studied.Indirect competitive ELISA was used to detect the antigenicity of the SC-mPEG-β-LG mixture.The results indicated that the highest reduction rate of antigenicity for modified products under different conditions was 70.2% at the reaction time of 8 h and at the same time,the highest modification degree detected by TNBS was 39.1%.Meanwhile,reaction time was the major factor affecting antigenicity reduction of β-LG modified by SC-mPEG.