Native Ambient Mass Spectrometry Imaging of Ligand-Bound and Metal-Bound Proteins in Rat Brain
Native Ambient Mass Spectrometry Imaging of Ligand-Bound and Metal-Bound Proteins in Rat Brain
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DOI：
10.1021/jacs.1c10032
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发表时间：
2022-02-09
影响因子：
15
通讯作者：
Cooper, Helen J.
中科院分区：
文献类型：
--
作者：
Sisley, Emma K.;Hale, Oliver J.;Cooper, Helen J.
蛋白质在其组织环境中的非共价相互作用的无标记空间图谱通过为更广泛地询问疾病进展、药物相互作用以及结构和分子生物学提供机会，有可能给生命科学研究带来革命性的变化。在这里，我们展示了内源性完整的非共价蛋白质-配体复合体在大鼠大脑中的质谱图。利用纳米解吸电喷雾电离技术绘制了一系列配体结合蛋白和金属结合蛋白在薄组织切片中的空间分布。用自顶向下的质谱仪直接从组织中鉴定蛋白质。三种GDP结合蛋白(ADP核糖化因子ARF3、ARF1和GTPase Ran)以其配体结合的形式被检测、鉴定和成像。多轮串联质谱学证实了该配体的性质。此外，还检测、鉴定和成像了金属结合蛋白小白蛋白-a和碳酸氢酶2，它们的天然形式分别为小白蛋白-α+2Ca(2+)和碳酸氢酶+锌。GTP酶Ran与GDP和镁离子结合均可检测到。通过自顶向下的质谱学鉴定了几种具有不同空间分布的天然单体蛋白质。蛋白质质谱学成像的空间分辨率为200微米。
Label-free spatial mapping of the noncovalent interactions of proteins in their tissue environment has the potential to revolutionize life sciences research by providing opportunities for the interrogation of disease progression, drug interactions, and structural and molecular biology more broadly. Here, we demonstrate mass spectrometry imaging of endogenous intact noncovalent protein-ligand complexes in rat brain. The spatial distributions of a range of ligand-bound and metal-bound proteins were mapped in thin tissue sections by use of nanospray-desorption electrospray ionization. Proteins were identified directly from the tissue by top-down mass spectrometry. Three GDP-binding proteins (ADP ribosylation factor ARF3, ARF1, and GTPase Ran) were detected, identified, and imaged in their ligand-bound form. The nature of the ligand was confirmed by multiple rounds of tandem mass spectrometry. In addition, the metal-binding proteins parvalbumin-a and carbonic anhydrase 2 were detected, identified, and imaged in their native form, i.e., parvalbumin-alpha + 2Ca(2+) and carbonic anhydrase + Zn2+. GTPase Ran was detected with both GDP and Mg2+ bound. Several natively monomeric proteins displaying distinct spatial distributions were also identified by top-down mass spectrometry. Protein mass spectrometry imaging was achieved at a spatial resolution of 200 mu m.