Photonics Research Group, INTEC, Ghent University - imec, Belgium.
Faraday Discuss. 2017 Dec 4;205:345-361. doi: 10.1039/c7fd00124j.
Surface-enhanced Raman scattering provides a promising technology for sensitive and selective detection of protease activity by monitoring peptide cleavage. Not only are peptides and plasmonic hotspots similarly sized, Raman fingerprints also hold large potential for spectral multiplexing. Here, we use a gold-nanodome platform for real-time detection of trypsin activity on a CALNNYGGGGVRGNF substrate peptide. First, we investigate the spectral changes upon cleavage through the SERS signal of liquid-chromatography separated products. Next, we show that similar patterns are detected upon digesting surface-bound peptides. We demonstrate that the relative intensity of the fingerprints from aromatic amino acids before and after the cleavage site provides a robust figure of merit for the turnover rate. The presented method offers a generic approach for measuring protease activity, which is illustrated by developing an analogous substrate for endoproteinase Glu-C.
表面增强拉曼散射（SERS）通过监测肽段切割，为敏感和选择性检测蛋白酶活性提供了一种很有前景的技术。不仅是因为肽段和等离子体热点的尺寸相似，而且拉曼指纹也具有很大的光谱复用潜力。在这里，我们使用金纳米穹顶平台对 CALNNYGGGGVRGNF 底物肽上的胰蛋白酶活性进行实时检测。首先，我们通过液质分离产物的 SERS 信号来研究切割过程中的光谱变化。接下来，我们表明，在消化表面结合的肽段时也可以检测到类似的模式。我们证明，在切割位点前后，来自芳香族氨基酸的指纹的相对强度为周转率提供了一个稳健的衡量标准。所提出的方法为测量蛋白酶活性提供了一种通用方法，我们通过开发内切蛋白酶 Glu-C 的类似底物来说明这一点。
