Mass spectrometry imaging (MSI) provides information on the spatial distribution of molecules within a biological substrate without the requirement for labeling. Its broad specificity, i.e., the capability to spatially profile any analyte ion detected, constitutes a major advantage over other imaging techniques. A separate branch of mass spectrometry, native mass spectrometry, provides information relating to protein structure through retention of solution-phase interactions in the gas phase. Integration of MSI and native mass spectrometry ("native MSI") affords opportunities for simultaneous acquisition of spatial and structural information on proteins directly from their physiological environment. Here, we demonstrate significant improvements in native MSI and associated protein identification of intact proteins and protein assemblies in thin sections of rat kidney by use of liquid extraction surface analysis on a state-of-the-art Orbitrap mass spectrometer optimized for intact protein analysis. Proteins of up to 47 kDa, including a trimeric protein complex, were imaged and identified.

中文翻译：

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直接从组织中原位质谱成像和自上而下原位鉴定完整蛋白质。

质谱成像 (MSI) 无需标记即可提供有关生物基质内分子空间分布的信息。其广泛的特异性，即对检测到的任何分析物离子进行空间分析的能力，构成了优于其他成像技术的主要优势。质谱的一个独立分支，即原生质谱，通过保留气相中的溶液相相互作用来提供与蛋白质结构相关的信息。MSI 和本机质谱（“本机 MSI”）的整合为直接从蛋白质的生理环境同时获取蛋白质的空间和结构信息提供了机会。这里，通过在最先进的 Orbitrap 质谱仪上使用液体提取表面分析，我们证明了天然 MSI 和完整蛋白质和蛋白质组装体在大鼠肾脏薄切片中的相关蛋白质鉴定方面的显着改进，该质谱仪针对完整蛋白质分析进行了优化。对高达 47 kDa 的蛋白质（包括三聚体蛋白质复合物）进行成像和鉴定。