Reversible pH-Driven Conformational Switching of Tethered Superoxide Dismutase with Gold Nanoparticle Enhanced Surface Plasmon Resonance Spectroscopy

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• 作者：Taewook Kang ; Surin Hong ; Inhee Choi ; Jung Jun Sung ; Younjung Kim ; Ji-Sook Hahn ; Jongheop Yi
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：October 4, 2006
• 年：2006
• 卷：128
• 期：39
• 页码：12870 - 12878
• 全文大小：529K
• 年卷期：v.128,no.39(October 4, 2006)
• ISSN：1520-5126

文摘

A new class of surface-immobilized protein nanomachines can be reversibly actuated by cyclingthe solution pH between 2.5 and 12.3, which induces a conformational change, thereby modulating thethickness of superoxide dismutase (SOD1) tethered to the Au thin film. By placing Au nanoparticles (AuNP)atop the immobilized SOD1 by means of a gold-thiol assembly, the nanoscale motion of SOD1 at theinterface produces mechanical work to lift and then lower the AuNP from the Au substrate by a distanceof ca. 3 nm and transduces this motion into an easily measurable reflectivity change in the surface plasmonresonance (SPR) spectrum. As-made supported conjugate consisting of SOD1 and AuNP is quite robustand stable, and its operation in response to pH variations, which mirrors the conformational changes ofresponsive SOD1 at the interface, is found to be highly reversible and reproducible. This is the firstdemonstration of the development of novel solid-state sensors and/or switching devices based on substrate-bound protein conformational changes and AuNP enhanced SPR spectroscopy.