Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States.
Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.
Anal Chem. 2024 Oct 1;96(39):15674-15681. doi: 10.1021/acs.analchem.4c03119. Epub 2024 Sep 16.
Owing to its ability to generate extensive fragmentation of proteins, ultraviolet photodissociation (UVPD) mass spectrometry (MS) has emerged as a versatile ion activation technique for the structural characterization of native proteins and protein complexes. Interpreting these fragmentation patterns provides insight into the secondary and tertiary structures of protein ions. However, the inherent complexity and diversity of proteins often pose challenges in resolving their numerous conformations. To address this limitation, we combined UVPD-MS with drift tube ion mobility, offering potential to acquire conformationally selective MS/MS information. A low-pressure drift tube (LPDT) Orbitrap mass spectrometer equipped with 193 nm UVPD capabilities enables the analysis of protein conformers through the analysis of arrival time distributions (ATDs) of individual fragment ions. ATDs of fragment ions are compared for different backbone cleavage sites of the protein or different precursor charge states to give information about regions of potential folding or elongation. This integrated platform offers promise for advancing our understanding of protein structures in the gas phase.
由于其能够产生广泛的蛋白质碎片化，因此紫外线光解（UVPD）质谱（MS）已成为一种通用的离子激活技术，可用于对天然蛋白质和蛋白质复合物进行结构表征。解释这些碎片化模式可深入了解蛋白质离子的二级和三级结构。然而，蛋白质的固有复杂性和多样性常常在解析其众多构象时带来挑战。为了解决这一限制，我们将 UVPD-MS 与漂移管离子淌度相结合，从而有可能获得构象选择性的 MS/MS 信息。配备 193nmUVPD 功能的低压漂移管（LPDT）Orbitrap 质谱仪可通过分析单个片段离子的到达时间分布（ATD）来分析蛋白质构象。比较不同蛋白质的骨干裂解部位或不同前体电荷状态的片段离子的 ATD，可提供有关潜在折叠或延伸区域的信息。该集成平台有望提高我们对气相中蛋白质结构的理解。
