A calcium-modulated plasmonic switch
A calcium-modulated plasmonic switch
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DOI：
10.1021/ja7109037
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发表时间：
2008-05-07
影响因子：
15
通讯作者：
Van Duyne, Richard P.
中科院分区：
文献类型：
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作者：
Hall, W. Paige;Anker, Jeffrey N.;Van Duyne, Richard P.
基于钙诱导的钙调蛋白构象变化的等离子体开关显示出响应于钙浓度变化的可逆波长调制。用新型钙调蛋白构建体角质酶-钙调蛋白-角质酶（CutCaMCut）功能化的局域表面等离子体共振（LSPR）传感器的消光最大值（lambda（max））可逆地移动2-3 nm。开发了波长分辨率（3 sigma）为1.5 x 10（-2）nm的高分辨率（HR）LSPR光谱仪，以实时检测这些波长调制，提供有关蛋白质动力学和结构的信息。从开放（Ca 2+结合）到封闭（无Ca 2+）钙调素的转化率显示出比反向过程快4倍，闭合速率为0.127 s（-1），开放速率为0.034 s（-1）。据我们所知，这种等离子体开关标志着首次使用LSPR光谱检测未标记蛋白质的可逆构象变化。
A plasmonic switch based on the calcium-induced conformational changes of calmodulin is shown to exhibit reversible wavelength modulations in response to changing calcium concentration. The extinction maximum (lambda(max)) of a localized surface plasmon resonance (LSPR) sensor functionalized with a novel calmodulin construct, cutinase-calmodulin-cutinase (CutCaMCut), reversibly shifts by 2-3 nm. A high-resolution (HR) LSPR spectrometer with a wavelength resolution (3 sigma) of 1.5 x 10(-2) nm was developed to detect these wavelength modulations in real-time, providing information about the dynamics and structure of the protein. The rate of conversion from open (Ca2+-bound) to closed (Ca2+-free) calmodulin is shown to be similar to 4-fold faster than the reverse process, with a closing rate of 0.127 s(-1) and opening rate of 0.034 s(-1). As far as we are aware, this plasmonic switch marks the first use of LSPR spectroscopy to detect reversible conformational changes in an unlabeled protein.