Metal-mediated ligand affinity chemistry

在化学学部生命过程化学（CLP）项目的支持下，英国肯塔基大学的Samuel G. Awuah正在开发新的化学工具来研究蛋白质的功能。修饰肽和蛋白质的化学试剂导致了各种各样的生物分子偶联物，加速了我们对蛋白质功能的理解和改进治疗方法的发展。尽管取得了进步，但现有方法的固有局限性使得新的化学工具成为蛋白质化学修饰和生物分子操作的必要条件，特别是在细胞或整个动物的天然位点内。Awuah研究小组将结合合成化学和分子生物学来研究特定氨基酸与金属基化合物对蛋白质调节的反应。如果成功，这项研究将建立对阐明复杂生物途径和蛋白质-蛋白质相互作用以及治疗方法和生物催化剂设计具有潜在长期影响的基本原则。该项目有潜力开发生物相容性金属介导的反应，将理想的配体不可逆地转移到预定的生物位置，从而为跨学科的科学家提供潜在的有用工具。本科学生，包括那些在STEM（科学、技术、工程和数学）领域未被充分代表的学生，将被引入无机、有机、生物和分析化学的交叉学科，以跨学科、基于发现的方式建立他们的信心和科学能力。最终的长期目标是充分利用英国的资源，提高STEM领域不同学生群体的参与度和保留率。 重要的努力正在进行中，以设计合成分子的选择性化学偶联，以扩大蛋白质的功能和治疗能力。肽和蛋白质中天然氨基酸的化学修饰（包括蛋白质-蛋白质相互作用（PPIs））已被证明具有挑战性，因为使用生物正交标记的合作伙伴仅限于N或c端，或者需要广泛的序列工程。重要的是，用于位点选择性蛋白偶联的反应需要具有化学选择性、区域选择性和在温和的生理相关条件下操作。本项目旨在开发金属介导的半胱氨酸和赖氨酸芳基化作为生物偶联的精细工具，并利用该工具探索选定肽和蛋白质的结构-功能关系，以建立这种S-和n -芳基化策略的细胞内靶电位。提出的工作的目的是研究半胱氨酸/赖氨酸芳基化与金基试剂；进行蛋白质的结构-功能研究，探索人类蛋白质组中赖氨酸的反应性和配体性。如果成功的话，这个项目中正在进行的研究可以通过引入强大的方法来选择性地修饰肽和蛋白质的天然位点，为化学生物学中长期存在的问题提供关键的解决方案。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 Chemistry of Life Processes (CLP) Program in the Division of Chemistry, Samuel G. Awuah of the University of Kentucky (UK) is developing new chemical tools to study protein function. Chemical reagents that modify peptides and proteins have led to a wide variety of biomolecule conjugates that has accelerated our understanding of protein function and the development of improved therapeutics. Despite the advancement, inherent limitations of current methods make new chemical tools a necessity for protein chemical modification and biomolecule manipulation particularly within their native sites in cells or whole animals. The Awuah research team will apply a combination of synthetic chemistry and molecular biology to study reactions of specific amino acids with metal-based compounds towards protein modulation. If successful, this study will establish fundamental principles that have potential long-term impact for elucidating complex biological pathways and protein-protein interactions as well as the design of therapeutics and biocatalysts. The project has the potential to develop biocompatible metal-mediated reactions that transfer desirable ligands to intended biological locations irreversibly, thusly providing a potentially useful tool for scientists across disciplines. Undergraduate students including those of underrepresented in the STEM (science, technology, engineering and mathematics) fields are to be introduced to interdisciplinary science at the interface of inorganic, organic, biological, and analytical chemistry, to build their confidence and scientific abilities in an interdisciplinary, discovery-based manner. The ultimate long-term goal is to greatly leverage the resources at UK to increase the participation and retention of diverse student groups in STEM fields.  Significant efforts are underway to design site-selective chemical conjugation of synthetic molecules to expand the functional and therapeutic capacity of proteins. The chemical modification of natural amino acids in peptides and proteins including protein-protein interactions (PPIs) has proved challenging due to the use of a bioorthogonally-labeled partner restricted to the N- or C-terminus or the need for extensive sequence engineering. Importantly, the reactions employed in site-selective protein conjugation need to be chemoselective, regioselective, and operational under mild, physiologically relevant conditions. This project aims to develop metal-mediated cysteine and lysine arylation as an elaborate tool for bioconjugation, and to utilize this tool to explore structure-function relationships on select peptides and proteins to establish the intracellular target potential of this S- and N-arylation strategy. The aims of the proposed work are to investigate cysteine/lysine arylation with gold-based reagents; to conduct structure-function studies on proteins and to explore lysine reactivity and ligandability within the human proteome. If successful, the studies being undertaken in this project could provide critical solutions to longstanding problems in chemical biology by introducing powerful methods to selectively modify peptides and proteins within their native sites.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.