Dynamic Nuclear Polarization Illuminates Key Protein–Lipid Interactions in the Native Bacterial Cell Envelope
Dynamic Nuclear Polarization Illuminates Key Protein–Lipid Interactions in the Native Bacterial Cell Envelope
复制标题
动态核极化揭示了天然细菌细胞包膜中关键蛋白质与脂质的相互作用
DOI：
10.1021/acs.biochem.3c00262
复制
发表时间：
2023
期刊：
影响因子：
2.9
通讯作者：
Marassi, Francesca M.
中科院分区：
文献类型：
--
作者：
Kent, James E.;Ackermann, Bryce E.;Debelouchina, Galia T.;Marassi, Francesca M.
阐明天然环境中蛋白质的结构和相互作用是结构生物学的基本目标。核磁共振（NMR）光谱法非常适合这项任务，但往往受到低灵敏度，特别是在复杂的生物环境。在这里，我们使用一种称为动态核极化（DNP）的灵敏度增强技术来克服这一挑战。我们应用DNP捕获外膜蛋白Ail的膜相互作用，Ail是鼠疫耶尔森氏菌宿主入侵途径的关键组成部分。我们表明，在天然细菌细胞包膜的DNP增强的NMR光谱AIL很好地解决和丰富的相关性，是不可见的，在传统的固态NMR实验。此外，我们证明了DNP捕获蛋白质和周围脂多糖层之间难以捉摸的相互作用的能力。我们的研究结果支持一个模型，其中细胞外环精氨酸残基重塑膜环境，这是一个过程，是至关重要的主机入侵和发病机制。
Elucidating the structure and interactions of proteins in native environments is a fundamental goal of structural biology. Nuclear magnetic resonance (NMR) spectroscopy is well suited for this task but often suffers from low sensitivity, especially in complex biological settings. Here, we use a sensitivity-enhancement technique called dynamic nuclear polarization (DNP) to overcome this challenge. We apply DNP to capture the membrane interactions of the outer membrane protein Ail, a key component of the host invasion pathway ofYersinia pestis. We show that the DNP-enhanced NMR spectra of Ail in native bacterial cell envelopes are well resolved and enriched in correlations that are invisible in conventional solid-state NMR experiments. Furthermore, we demonstrate the ability of DNP to capture elusive interactions between the protein and the surrounding lipopolysaccharide layer. Our results support a model where the extracellular loop arginine residues remodel the membrane environment, a process that is crucial for host invasion and pathogenesis.