DiCecco Liza-Anastasia, Berry Samantha, Jonaid G M, Solares Maria J, Kaylor Liam, Gray Jennifer L, Bator Carol, Dearnaley William J, Spilman Michael, Dressel-Dukes Madeline J, Grandfield Kathryn, McDonald Esstman Sarah M, Kelly Deborah F
Department of Biomedical Engineering, Pennsylvania State University; Department of Materials Science and Engineering, McMaster University.
Department of Biomedical Engineering, Pennsylvania State University.
J Vis Exp. 2022 Jul 20(185). doi: 10.3791/63856.
Interest in liquid-electron microscopy (liquid-EM) has skyrocketed in recent years as scientists can now observe real-time processes at the nanoscale. It is extremely desirable to pair high-resolution cryo-EM information with dynamic observations as many events occur at rapid timescales - in the millisecond range or faster. Improved knowledge of flexible structures can also assist in the design of novel reagents to combat emerging pathogens, such as SARS-CoV-2. More importantly, viewing biological materials in a fluid environment provides a unique glimpse of their performance in the human body. Presented here are newly developed methods to investigate the nanoscale properties of virus assemblies in liquid and vitreous ice. To accomplish this goal, well-defined samples were used as model systems. Side-by-side comparisons of sample preparation methods and representative structural information are presented. Sub-nanometer features are shown for structures resolved in the range of ~3.5-Å-10 Å. Other recent results that support this complementary framework include dynamic insights of vaccine candidates and antibody-based therapies imaged in liquid. Overall, these correlative applications advance our ability to visualize molecular dynamics, providing a unique context for their use in human health and disease.
近年来，随着科学家们现在能够在纳米尺度上观察实时过程，对液-电子显微镜（liquid-EM）的兴趣急剧上升。将高分辨率冷冻电镜信息与动态观察相结合是非常可取的，因为许多事件发生在快速的时间尺度上——在毫秒范围内或更快。对柔性结构的深入了解也有助于设计对抗新兴病原体（如SARS-CoV-2）的新型试剂。更重要的是，在流体环境中观察生物材料能让我们独特地了解它们在人体中的性能。本文介绍了新开发的用于研究液体和玻璃态冰中病毒聚集体纳米尺度特性的方法。为了实现这一目标，使用了定义明确的样品作为模型系统。展示了样品制备方法的并列比较和代表性结构信息。对于在约3.5埃至10埃范围内解析的结构，展示了亚纳米特征。支持这一互补框架 的其他近期结果包括对液体中成像的候选疫苗和基于抗体的疗法的动态见解。总体而言，这些相关应用提高了我们可视化分子动力学的能力，为其在人类健康和疾病中的应用提供了独特的背景。
