【作者】 张小霞； 刘允军； 严卫星； 徐海滨；

【Author】 zhang xiaoxia Liu yunjum~1 Yan weixing~2 Xu haibin~3 National Center for Health Inspection and Supervision,100007,Beijing

【机构】 卫生部卫生监督中心； 中国农业大学生物生物学院； 中国疾病预防控制中心营养与食品安全所； 国家食品药品监督管理局；

【摘要】 目的以大肠杆菌表达的抗虫蛋白 Cry1Ie 为模式蛋白,检测其在胃模拟消化液(SGF) 和99℃水浴中加热的稳定性情况,为转 Cry1Ie 基因玉米的食用安全性提供依据。方法 Cry1Ie 蛋白分别在 SGF 各 pH 系列1．0、1．5、2．0、4．0、6．0及99℃热水浴中消化,设立阴性对照小牛血清白蛋白(BSA)和阳性对照卵清蛋白,用 Western blotting 方法分析 Cry1Ie 蛋白各时间点的降解情况。结果 Cry1Ie 在 pH1．0和 pH1．5的胃模拟消化液条件下,消化4分钟经 Western blotting 分析未检测到目的蛋白质；在 pH2．0、4．0、6．0的胃模拟消化液条件下,消化1小时仍能检测到目的蛋白质；Cry1Ie 蛋白在99℃热水浴中加热5分钟经 Western blotting 分析检测不到目的蛋白质；阴性对照小牛血清白蛋白(BSA)在 pH1．0和 pH1．5的胃模拟消化液条件下消化15秒钟完全降解,在99℃热水浴中加热5分钟检测不到；阳性对照卵清蛋白2小时未见降解, 在99℃热水浴中加热2小时仍可见明显的蛋白质痕迹。结论 Cry1Ie 在生理条件胃模拟消化液 (pH＜2)条件下很快降解,在99℃热水浴热条件下迅速分解,提示 Cry1Ie 蛋白不耐胃蛋白酶不耐热,为转 Cry1Ie 基因玉米的安全性提供基础性资料,并为摸索转基因食品中外来蛋白的食品安全性评价的方法奠定了技术平台。更多还原

【Abstract】 Objective In this study,Cry1Ie expression protein from Bacillus coli.is used as a model protein to examine the stability in stimulated gastric fluid(SGF)and 99℃ heate water in order to provide edible safety evidences of transgenic Cry1Ie maize.Methods Cry1Ie protein is digested in stimulated gastric fluid(SGF)in difference dozes times pH1.0 1.5 2.0.4.0 6.0 of different time dozes and in 99℃ heat water in different time dozes,following Albumin Bovine Serum(BSA)as a negative protein and Albumin Chicken egg as a positive protein.Their results were detected by western blotting analysis.Results In SGF of pH 1.0 and pH1.5 Cry1Ie was completely digested after 4minute through wetem blotting analysis,in SGF of pH2.0 pH4.0 pH6.0 Cry1Ie was not digested after 1 hour through western blotting analysis, in BSA was fully digested after 15second,Albumin Chicken egg was not digested after 2hour;Cry1Ie was almost completely broken up in 5minute in 99℃ heat water through western blotting analysis,following BSA as a negative protein control completely disappearing after 5minute and Albumin Chicken egg as a positive protein control completely appearing after 120minute.Conelnsion Cry1Ie was quickly broken up in 99℃ heat water,quickly degraded in SGF of pH ＜2.This results will hint that Cry1Ie cannot endure pepsin and heat,offer basal information to safety evaluation for new transgenic Cry1Ie maize,meanwhile establish foundation definitely for food safety assessment of exogenous proteins derived from modem biological technique.更多还原