CAREER: The Lassa Virus Fusion Domain - A Cyclic Approach to Revealing the Molecular Chemistry behind Membrane Fusion

在化学系CLP项目的支持下，来自马里兰大学帕克分校的Jin Woo Lee正在研究拉沙病毒（LASV）膜融合启动背后的分子化学。LASV是沙粒病毒家族的一员，目前在西非流行，全世界报告的LASV感染发生率不断上升。世界卫生组织（世卫组织）已经在2018年注意到LASV的大流行潜力，并表示需要紧急和优先研究该病毒。膜融合是LASV生命周期的一个关键组成部分，它允许病毒通过一个尚不清楚的化学过程将其遗传信息传递到靶细胞中。这一过程被认为是由特定环境条件触发的特殊融合机制促进的。这种机制的一个这样的例子是融合域（FD），它主要与膜融合的起始有关。该研究旨在从分子水平上确定FD如何启动膜融合过程。这些信息通常是新的治疗设计的先决条件，这些设计可能有助于阻止病毒的生命周期，预防和/或治疗LASV感染。同时，将实施教育拓展计划，重点是为即将入学的转学生和当地高中生提供获得实际科学研究经验的机会。该计划的目的是提高科学、技术、工程和数学（STEM）领域学生的保留率和入学率。LASV膜融合的启动依赖于FD，它存在于病毒表面的病毒糖蛋白中。这个结构域在沙粒病毒家族中是保守的，并且在结构上也是不同的，包含一个n端融合肽（FP）和一个内部融合环（FL）。该研究的首要目标是了解FD的潜在化学成分如何促进膜融合的启动。具体而言，将研究LASV FD中多个聚变区域的结构和功能作用以及环境条件的影响。采用循环方法利用溶液核磁共振（NMR）光谱来阐明LASV FD的结构重排。核磁共振工作将通过等温滴定量热法（ITC）和体外脂质混合融合试验进行热力学和动力学研究。所提到的框架允许FD作为肽和完整病毒糖蛋白的背景下进行研究。后者需要一种涉及特定标记和纳入脂质双分子层的新方法，这两种方法都将被实施，以提供更多的生理相关性。研究结束后，将填补关于LASV膜融合的主要知识空白，并为研究其他病毒fd建立框架。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the CLP program in the Division of Chemistry, Jin Woo Lee from the University of Maryland, College Park is studying the molecular chemistry behind the initiation of Lassa Virus (LASV) membrane fusion. LASV is a member of the Arenavirus family that is currently endemic to West Africa, and there is an increasing incidence of LASV infection reported worldwide. The pandemic potential of LASV has already been noted by the World Health Organization (WHO) in 2018, which stated that the virus requires urgent and prioritized research. Membrane fusion is a key component of the LASV lifecycle that allows the virus to deliver its genetic information into the target cell through a chemical process that is not well understood. The process is thought to be facilitated by specialized fusion machinery that undergoes structural transitions triggered by specific environmental conditions. One such example of this machinery is the fusion domain (FD), which is predominately associated with the initiation of membrane fusion. The research aims to identify, on a molecular level, exactly how the FD initiates the process of membrane fusion. Such information is often a prerequisite for novel therapeutic design that may serve to arrest the viral lifecycle and prevent and/or treat LASV infection. Simultaneously, an educational outreach program will be implemented focused on providing opportunities for incoming transfer students as well as local high school students to gain practical scientific research experience. The aim of the program is to improve both the retention and enrollment of students within the science, technology, engineering, and mathematics (STEM) fields.The initiation of LASV membrane fusion relies on the FD, which resides within the viral glycoprotein found on the viral surface. This domain is well conserved across the Arenavirus family and is also structurally distinct, containing both an N-terminal fusion peptide (FP) and an internal fusion loop (FL). The overarching goal of the research is to understand how the underlying chemistry of the FD contributes to the initiation of membrane fusion. Specifically, the structural and functional roles of multiple fusogenic regions within the LASV FD and the impacts of environmental conditions will be examined. A cyclic approach will be employed utilizing solution nuclear magnetic resonance (NMR) spectroscopy to elucidate the structural rearrangement of the LASV FD. The NMR work will be complemented by thermodynamic and kinetic investigations through isothermal titration calorimetry (ITC) and in vitro lipid mixing fusion assays. The framework mentioned allows the investigation of the FD as both a peptide and within the context of the full viral glycoprotein. The latter requires a novel approach involving specific labeling and incorporation into a lipid bilayer, both of which will be implemented in order to provide more physiological relevance. Upon conclusion of the research, a major knowledge gap regarding LASV membrane fusion will be filled and a framework for studying other viral FDs will be established.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.