High Resolution Tools for Structural Biology

在化学系化学测量和成像计划的支持下，加州大学河滨分校的Ryan Julian教授和他的团队正在开发方法来提高我们确定蛋白质结构的能力-蛋白质结构是生物学中各种重要功能的关键参与者，包括充当细胞内和细胞间能量和通信的工厂。朱利安实验室正在开发新的方法，可以揭示蛋白质分子不同部分之间的距离，提供高分辨率的结构，有助于理解蛋白质的功能以及它们的功能可能是如何在分子水平上被操纵的。使用的主要工具是质谱仪，这是一种可以用于微量样品的快速技术。提高了通过质谱学确定结构的能力，加速了我们对关键生物行为的理解。一群不同的研究生和本科生正在进行这项研究，并接受了宝贵的培训，这将为他们在未来推动科学技术的发展做好准备。朱利安博士和他的团队还致力于针对来自代表性不足群体的高中生的外展努力。朱利安团队正在开发利用特定残基之间的能量转移和共价交联来确定高分辨率蛋白质结构的新方法，以便建立多个定义明确的距离约束，这些约束可以与计算结合使用，以产生原子定义的气相结构。能量转移方法在确定高分辨结构方面有几个关键优点，包括：1)直接探测蛋白质亚结构，允许确定单个蛋白质中的多个距离限制；2)使用天然残基作为供体和受体，允许通过标准的定点突变安装任何所需的氨基酸；以及3)高度选择性的光化学裂解，提供高灵敏度和明确的结果解释。利用质谱学的速度和灵敏度，气相结构生物学可以处理不受X射线结晶学或核磁共振影响的蛋白质。这项研究补充和扩展了从更广泛使用的、较低分辨率的方法获得的信息。新方法可以在未经修改的商业仪器上进行，增加了高分辨率测量的可及性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Ryan Julian and his group at the University of California - Riverside are developing methods to improve our ability to determine the structure of proteins - key actors in biology for diverse and important functions that include serving as factories for energy and communications within and among cells. The Julian lab is developing new methods that can reveal the distance between different parts of a protein molecule, providing high resolution structures which contribute to understanding how proteins function and how their function might be manipulated at a molecular level. The primary tool used is mass spectrometry - a rapid technique that can be used with minuscule amounts of sample. Enhanced capabilities for structure determination by mass spectrometry are accelerating our understanding of crucial biological actors. A diverse group of graduate and undergraduate students are carrying out this research and receiving valuable training that will prepare them to push the boundaries of science and technology forward in the future. Dr. Julian and his team are also engaged in outreach efforts targeting high school students from underrepresented groups. The Julian group is developing new approaches to determining high resolution protein structures using energy transfer and covalent crosslinking between specific residues in order to establish multiple, well-defined distance constraints that can be used in conjunction with calculations to yield atomically-defined gas-phase structures. The energy-transfer approach has several key advantages for determination of high resolution structure, including: 1) direct probing of protein substructure, allowing the determination of multiple distance constraints in a single protein; 2) use of native residues for the donor and acceptor, allowing for the installation of any required amino acids by standard site-directed mutagenesis; and 3) extremely selective photochemical cleavage of bonds affording high sensitivity and unambiguous interpretation of the results. Utilizing the speed and sensitivity of mass spectrometry, gas-phase structural biology can tackle proteins not amenable to x-ray crystallography or nuclear magnetic resonance. This research complements and expands the information available from more widely used, lower-resolution approaches. The new methods can be conducted on unmodified, commercially available instruments, increasing the accessibility of high-resolution measurements.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.