PDF(Pubmed)
Abstract：
Microcrystal electron diffraction (MicroED) has emerged as a powerful technique for unraveling molecular structures from microcrystals too small for X-ray diffraction. However, a significant hurdle arises with plate-like crystals that consistently orient themselves flat on the electron microscopy grid. If the normal of the plate correlates with the axes of the crystal lattice, the crystal orientations accessible for measurement are restricted because the crystal cannot be arbitrarily rotated. This limits the information that can be acquired, resulting in a missing cone of information. We recently introduced a novel crystallization strategy called suspended drop crystallization and proposed that crystals in a suspended drop could effectively address the challenge of preferred crystal orientation. Here we demonstrate the success of the suspended drop approach in eliminating the missing cone in two samples that crystallize as thin plates: bovine liver catalase and the SARS‑CoV‑2 main protease (Mpro). This innovative solution proves indispensable for crystals exhibiting systematic preferred orientations, unlocking new possibilities for structure determination by MicroED.
摘要：
微晶电子衍射（MicroED）已经成为一种强大的技术，可以从X射线衍射太小的微晶中解开分子结构。然而,一个重要的障碍出现与板状晶体一致定向自己平在电子显微镜网格。如果板的法线与晶格的轴相关，可用于测量的晶体取向受到限制，因为晶体不能任意旋转。这限制了可以获取的信息，导致信息缺失。我们最近引入了一种称为悬浮液滴结晶的新型结晶策略，并提出悬浮液滴中的晶体可以有效地解决优选晶体取向的挑战。在这里，我们证明了悬浮滴法在消除两个样品中缺失的锥体的成功，这些样品结晶为薄板：牛肝过氧化氢酶和SARS-CoV-2主要蛋白酶（Mpro）。这种创新的解决方案被证明是必不可少的晶体表现出系统的首选取向，为MicroED确定结构解锁新的可能性。
