CAREER: Secondary Amine Selective Petasis (SASP) Bioconjugation

有了这个奖项，化学部门的生命过程化学项目资助了奥本大学的莫妮卡·拉吉博士，以开发一种化学方法，可以选择性地标记生物分子上的特定位点，而不存在其他类似的位点。在这种情况下，已知特定标记的位点“打开”或“关闭”细胞内负责细胞生长的非常重要的功能，以及从一个细胞到另一个细胞的信息传递。该提案旨在使用新的化学标记方法来更好地了解活性位点的生物学意义，即它们如何控制细胞功能。Raj博士开发了基于经典化学反应的创新应用的方法，用于可视化生物分子并用染料标记它们。该项目还通过允许来自未被充分代表的少数民族的研究生和本科生获得有机化学和生物化学方面的培训，支持不断增加科学领域多样性的努力。外展活动吸引高中生（尤其是女性和少数族裔），通过有趣的实验让他们了解科学的基本概念，最终鼓励他们在STEM领域学习和从事学术事业。在蛋白质表面活性氨基酸侧链存在的情况下，能够针对单个位点上特定官能团的化学策略是有限的。更罕见的是，有机反应可以在足够温和的条件下进行，以标记生物分子。为了解决这些挑战，本研究项目基于经典的有机Petasis反应开发了一种新的多组分生物偶联方法，用于选择性标记含有仲胺的蛋白质。该方法用于标记含有翻译后修饰（PTMs）的单甲基赖氨酸在不同货物的蛋白质上。这些单甲基赖氨酸PTMs的失调与各种不同的生物功能失调有关，但选择性检测单甲基赖氨酸PTMs的化学方法仍然缺乏。该研究提供了一种高选择性的化学工具，可以有效地检测单甲基赖氨酸PTMs，这些PTMs不仅存在于组蛋白蛋白上，而且存在于其他蛋白质上，并指示各种蛋白质相互作用和功能。因此，提出的研究有很大的潜力来进一步了解这些PTMs如何调节各种细胞信号过程以及PTMs本身是如何被调节的。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 this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Monika Raj from Auburn University to develop a chemical method that can selectively label a specific site on a biomolecule in the presence of sea of other similar sites. In this case, the specifically labeled site is known to "turn on" or "turn off" very important functions inside the cell which are responsible for cell growth, as well as the transfer of information from one cell to another. The proposal aims to use the new chemical labeling method to better understand the biological significance of the reactive sites, that is how they control cellular function. Dr. Raj develops methods based on innovative applications of classical chemical reactions for visualizing biomolecules and tagging them with dye. This project also supports continued efforts toward increasing diversity in science fields by allowing graduate and undergraduate students from underrepresented minorities to gain training in both organic chemistry and biochemistry. Outreach activities engage high school students (especially women and underrepresented minorities) and expose them to basic concepts of science through fun experimentation, ultimately encouraging them to pursue studies and academic careers in STEM fields.Chemical strategies that can target a particular functional group at a single site in the presence of reactive amino acid side chains on protein surfaces are limited. Even more rare are organic reactions that can proceed under conditions mild enough to label biomolecules. To address these challenges, this research project develops a new multicomponent bioconjugation method based on the classical organic Petasis reaction for selective labeling of proteins containing secondary amines. This method is employed for labeling mono-methyl lysine containing posttranslational modifications (PTMs) on proteins with various cargoes. The dysregulation of these mono methyl lysine PTMs has been linked to a variety of different biological malfunctions, yet the chemical methods for selective detection of mono methyl lysine PTMs are still lacking. This research provides a highly selective chemical tool that can effectively detect mono methyl lysine PTMs which, are present not only on histone proteins but also on other proteins and dictate various protein-protein interactions and functions. Thus, the proposed research has a great potential to further our understanding of how these PTMs regulate various cellular signaling processes and how the PTMs themselves are regulated.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.