基于纳米毛细管的非变性质谱分析

非变性质谱利用电喷雾电离质谱技术从非变性缓冲溶液中研究自然折叠状态下的蛋白质、核酸及其复合物，是大型蛋白质组装体、蛋白质-药物复合物、核酸-配体复合物的结构、组成及其相互作用解析的重要工具。生化缓冲溶液中的非挥发性盐能提供足够的离子强度和适宜的pH值，以维持蛋白质、核酸分子折叠和结合状态，但通常与电喷雾电离质谱不兼容。基于纳米毛细管的电喷雾电离具备强大的基质耐受能力，为直接从生理或近生理缓冲溶液中完成蛋白质及其复合物的高效离子化提供了可能，极大地促进了近年来非变性质谱的应用研究。本文综述了纳米毛细管的制备与表征方法及其尺寸和界面性质导致的电离行为特性，回顾了近10年来纳米毛细管在非变性质谱中的应用研究进展。

Native Mass Spectrometry Enabled by Nano-capillary

Native mass spectrometry (native MS) has emerged as an important analytical tool for the investigation of structures, compositions and intermolecular interactions of macromolecular assemblies, protein-drug complexes and nucleic acid-ligand complexes, directly from buffers that maintain their naturally folded structures and natively bound states. The non-volatile salts in biochemical buffers are essential for providing the sufficient ionic strength and appropriate pH, which are needed to maintain the native folded states of proteins and nucleic acids, as well as their binding states with various other molecules through the weak noncovalent interactions. Benefit from its unique matrix tolerance, a nanoscale capillary (nano-capillary) is capable of directly producing ions of proteins, nucleic acids and their ligand-bound complexes from physiological or near physiological buffers, which has greatly promoted the progress in native MS. In this review, the fabrication and characterization of a nano-capillary, the unique ionization behaviors caused by the ultrasmall size as well as its inner surface property of a nano-capillary were reviewed. The applications of native MS that employed a nano-capillary emerged during the last decade were also summarized.