Controlling antibody orientation on charged self-assembled monolayers
Controlling antibody orientation on charged self-assembled monolayers
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DOI：
10.1021/la026498v
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发表时间：
2003-04-01
期刊：
影响因子：
3.9
通讯作者：
Jiang, SY
中科院分区：
文献类型：
--
作者：
Chen, SF;Liu, LY;Jiang, SY
抗体在表面的取向对生物传感器的性能至关重要。由于抗体分子内的电荷分布，人们希望通过调节微环境(例如，表面和溶液性质)来控制吸附的抗体的取向。在这项工作中，我们用表面等离子体共振(SPR)生物传感器研究了两种类型的抗人绒毛膜促性腺激素(抗hCG)在NH_2(带正电)和COOH(带负电)端基自组装单分子膜(SAM)上的定位。用原子力显微镜对表面吸附的抗体分子进行了表征。SPR实验结果表明，IgG1型抗体在NH2表面的定向性好于在COOH表面的定向度，说明在NH2表面有较高的hCG/抗hCG吸附比。然而，对于IgG2a型抗体，抗原与抗体的比率，从而吸附的IgG2a在NH2和COOH端基的SAM表面上的取向是相似的。表面电荷对IgG2a取向的影响小于IgG1，这是因为与IgG1相比，IgG2a的偶极矩较小。这项工作不仅为微环境如何影响蛋白质在表面上的行为提供了一个基本的理解，而且也为生物传感器和生物材料等应用的表面设计提供了有用的指南。
The orientation of antibodies on surfaces is critical to the performance of biosensors. Due to the charge distribution within an antibody molecule, it is hoped that the orientation of adsorbed antibodies can be controlled by adjusting microenvironments (e.g., surface and solution properties). In this work, we investigated the orientations of two types of monoclonal anti-human chorionic gonadotropin (anti-hCG) adsorbed on NH2 (positively charged) and COOH (negatively charged) terminated self-assembled monolayers (SAMs) by surface plasmon resonance (SPR) biosensors. Adsorbed antibody molecules on surfaces were also characterized by atomic force microscopy. Results show that the orientation of the IgG1 type antibody is better on the NH2 surface than on the COOH surface, as indicated by a higher hCG to adsorbed anti-hCG ratio on the NH2 surface from SPR experiments. However, for the IgG2a type antibody, the antigen-to-antibody ratio, and thus the orientation of the adsorbed IgG2a, is similar on the NH2- and COOH-terminated SAM surfaces. Surface charge affects the orientation of IgG2a less than IgG1 due to the smaller dipole moment of IgG2a compared to IgG1. This work provides not only a fundamental understanding of how microenvironments affect protein behavior on surfaces but also a useful guide to designing surfaces for applications, such as biosensors and biomaterials.