对于对空气敏感的酶蛋白的无氧冷EM协议.
Rebeccah A Warmack1,2, Belinda B Wenke3, Thomas Spatzal3
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA. rwarmack@caltech.edu.
Nature protocols
|April 4, 2024
概括
这项研究引入了单粒子冷电子显微镜 (cryoEM) 的无氧工作流,使得像酶酶等对空气敏感的生物分子的高分辨率结构分析成为可能.
科学领域:
- 结构生物学 结构生物学
- 生物化学 生物化学
- 显微镜的使用方法
背景情况:
- 单粒子冷电子显微镜 (cryoEM) 对于原子分辨率研究至关重要.
- 目前的冷EM方法主要集中在有氧样本上,限制了对空气敏感生物系统的研究.
- 对空气敏感的酶和微生物在结构生物学中至关重要,但仍未得到充分研究.
研究的目的:
- 开发和详细介绍单粒子冷却EM的无氧工作流程.
- 为了使氧气敏感蛋白质,特别是酶酶的高分辨率结构确定.
- 为其他对空气敏感的生物样本提供可适应的协议.
主要方法:
- 使用施伦克线和无气室在惰性大气中进行样品制备.
- 包含一个蛋白质标签来监控氧气暴露.
- 在一个专门的无氧室内调整了一个沉浸式冷装置,用于冷EM电网的准备.
- 实现了定制的真空端口,以安全地疏散易燃蒸气.
主要成果:
- 通过使用开发的无氧冷EM工作流程,成功获得了基酶蛋白的高分辨率结构.
- 证明了该协议的有效性,用于表征对空气敏感的酶.
- 建立了一个包括无氧样本生成和冷EM准备在内的综合性协议.
结论:
- 开发的无氧冷EM工作流程成功克服了研究对空气敏感生物系统的局限性.
- 这种方法显著推进了像酶这样的酶的结构生物学.
- 该协议可适应各种受控气体环境和对氧敏感蛋白质.
相关概念视频
Cryo-electron Microscopy
3.3K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
3.3K
Preparation of Samples for Electron Microscopy
5.4K
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
5.4K


