Ondrus Alison E, Lee Hsiao-lu D, Iwanaga Shigeki, Parsons William H, Andresen Brian M, Moerner W E, Du Bois J
Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA 94305-5080, USA.
Chem Biol. 2012 Jul 27;19(7):902-12. doi: 10.1016/j.chembiol.2012.05.021.
A desire to better understand the role of voltage-gated sodium channels (Na(V)s) in signal conduction and their dysregulation in specific disease states motivates the development of high precision tools for their study. Nature has evolved a collection of small molecule agents, including the shellfish poison (+)-saxitoxin, that bind to the extracellular pore of select Na(V) isoforms. As described in this report, de novo chemical synthesis has enabled the preparation of fluorescently labeled derivatives of (+)-saxitoxin, STX-Cy5, and STX-DCDHF, which display reversible binding to Na(V)s in live cells. Electrophysiology and confocal fluorescence microscopy studies confirm that these STX-based dyes function as potent and selective Na(V) labels. The utility of these probes is underscored in single-molecule and super-resolution imaging experiments, which reveal Na(V) distributions well beyond the optical diffraction limit in subcellular features such as neuritic spines and filopodia.
更好地理解电压门控钠通道（Na(V)s）在信号传导中的作用及其在特定疾病状态下的失调，促使人们开发用于研究它们的高精度工具。自然界进化出了一系列小分子试剂，包括贝类毒素（+）-石房蛤毒素，它们与特定Na(V)亚型的细胞外孔结合。如本报告所述，从头化学合成使得制备荧光标记的（+）-石房蛤毒素衍生物STX-Cy5和STX-DCDHF成为可能，它们在活细胞中与Na(V)s表现出可逆结合。电生理学和共聚焦荧光显微镜研究证实，这些基于STX的染料可作为有效的选择性Na(V)标记物。这些探针的实用性在单分子和超分辨率成像实验中得到了强调，这些实验揭示了在亚细胞特征如神经棘和丝状伪足中，Na(V)的分布远远超出了光学衍射极限。
