Department of Materials Sciences and Engineering, Yonsei University, 134 Shin-chon-dong, Seo-dae-mun-gu, Seoul 120-749, Republic of Korea.
Enzyme Microb Technol. 2013 Jul 10;53(2):118-22. doi: 10.1016/j.enzmictec.2013.03.022. Epub 2013 Apr 12.
Escherichia coli cells with autodisplayed Z-domains could increase the sensitivity of immunoassays by immobilizing antibodies in a controlled orientation. In the work presented here, E. coli cells with autodisplayed Z-domains were immobilized to magnetic beads for subsequent immunoassay. In comparing conventional immunoassay using the E. coli cells with autodisplayed Z-domains, the magnetic-bead-based immunoassay improved immunoassay efficiency by minimizing the loss of E. coli cells during repeated centrifugation steps during washing. For the immobilization of E. coli cells to magnetic beads, the magnetic beads were modified with poly-l-lysine to bind to negatively charged E. coli cells. During the surface modification process, physical parameters such as the surface charge and size of the magnetic beads were analyzed to confirm the formation of E. coli-magnetic bead complexes. To test the feasibility of the magnetic-bead-based immunoassay, horseradish peroxidase (HRP) was used as a model analyte, and a biomarker for inflammatory diseases, C-reactive protein (CRP), was used for a demonstration of an application in medical diagnosis.
具有自动展示 Z 结构域的大肠杆菌细胞可以通过将抗体固定在受控的方向上来提高免疫测定的灵敏度。在本工作中，将具有自动展示 Z 结构域的大肠杆菌细胞固定在磁珠上，用于随后的免疫测定。在比较使用具有自动展示 Z 结构域的大肠杆菌细胞的常规免疫测定时，基于磁珠的免疫测定通过最小化在洗涤过程中反复离心步骤中大肠杆菌细胞的损失来提高免疫测定效率。为了将大肠杆菌细胞固定到磁珠上，使用聚赖氨酸对磁珠进行改性以与带负电荷的大肠杆菌细胞结合。在表面改性过程中，分析了诸如表面电荷和磁珠大小的物理参数，以确认大肠杆菌-磁珠复合物的形成。为了测试基于磁珠的免疫测定的可行性，使用辣根过氧化物酶（HRP）作为模型分析物，并且将用于炎症性疾病的生物标志物 C-反应蛋白（CRP）用于医疗诊断中的应用的演示。
