Mass Spectrometry Research Center, Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States.
Anal Chem. 2013 Aug 6;85(15):7191-6. doi: 10.1021/ac400902h. Epub 2013 Jul 19.
Transmembrane proteins are greatly underrepresented in data generated by imaging mass spectrometry (IMS) because of analytical challenges related to their size and solubility. Here, we present the first example of MALDI IMS of two highly modified multitransmembrane domain proteins, myelin proteolipid protein (PLP, 30 kDa) and DM-20 (26 kDa), from various regions of rat brain, namely, the cerebrum, cerebellum, and medulla. We utilize a novel tissue pretreatment aimed at transmembrane protein enrichment to show the in situ distribution of fatty acylation of these proteins, particularly of post-translational palmitoylation. Additionally, we demonstrate the utility of protease-encapsulated hydrogels for spatially localized on-tissue protein digestion and peptide extraction for subsequent direct coupling to LC-MS/MS for protein identification.
跨膜蛋白在成像质谱 (IMS) 生成的数据中严重代表性不足，因为其大小和溶解度与分析相关的挑战。在这里，我们展示了第一个多跨膜结构域蛋白髓鞘少突胶质细胞糖蛋白 (PLP，30 kDa) 和 DM-20（26 kDa）的 MALDI IMS 实例，这些蛋白来自大鼠脑的不同区域，包括大脑、小脑和延髓。我们利用一种新的组织预处理方法，旨在富集跨膜蛋白，以显示这些蛋白质的脂肪酸酰基化的原位分布，特别是翻译后棕榈酰化。此外，我们还展示了蛋白酶包封水凝胶在组织内蛋白质局部消化和肽提取方面的应用，以用于随后直接与 LC-MS/MS 进行偶联，用于蛋白质鉴定。
