德国马克斯·普朗克生物物理研究所Bonnie J. Murphy团队近期取得重要工作进展，他们研究提出了基于重构电子能量损失分析的单粒子重构中的元素映射。相关研究成果2024年10月24日在线发表于《自然—方法学》杂志上。

据介绍，对于通过冷冻电镜确定的大分子结构，目前还没有将元素映射到指定位置的技术，导致在活性和调节中起重要作用的金属和其他离子、辅因子、底物、抑制剂和脂质的分配错误。电子显微镜中的元素图谱对于耐受剂量的样品来说已经建立得很好，但对于生物样品来说，尤其是在低温保存状态下，这是一个挑战。

研究人员将电子能量损失光谱与单粒子图像处理相结合，以允许在低温保存的大分子复合物中进行元素映射。原理证明数据表明，重建电子能量损失（REEL）分析，允许对电子能量损失光谱数据进行三维重建，从而在复合物的许多副本上积累高总电子剂量。通过两个测试样本，研究人员证明这一方法能可靠定位丰富的元素。研究人员也指出了该方法的当前局限性和未来的潜在发展。

附：英文原文

Title: Elemental mapping in single-particle reconstructions by reconstructed electron energy-loss analysis

Author: Pfeil-Gardiner, Olivia, Rosa, Higor Vincius Dias, Riedel, Dietmar, Chen, Yu Seby, Lrks, Dominique, Kkelhan, Pirmin, Linck, Martin, Mller, Heiko, Van Petegem, Filip, Murphy, Bonnie J.

Issue&Volume: 2024-10-24

Abstract: For macromolecular structures determined by cryogenic electron microscopy, no technique currently exists for mapping elements to defined locations, leading to errors in the assignment of metals and other ions, cofactors, substrates, inhibitors and lipids that play essential roles in activity and regulation. Elemental mapping in the electron microscope is well established for dose-tolerant samples but is challenging for biological samples, especially in a cryo-preserved state. Here we combine electron energy-loss spectroscopy with single-particle image processing to allow elemental mapping in cryo-preserved macromolecular complexes. Proof-of-principle data show that our method, reconstructed electron energy-loss (REEL) analysis, allows a three-dimensional reconstruction of electron energy-loss spectroscopy data, such that a high total electron dose is accumulated across many copies of a complex. Working with two test samples, we demonstrate that we can reliably localize abundant elements. We discuss the current limitations of the method and potential future developments.

DOI: 10.1038/s41592-024-02482-5

Source: https://www.nature.com/articles/s41592-024-02482-5