DFG Cluster of Excellence livMatS @FIT-Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany.
Institute of Organic Chemistry, University of Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
J Am Chem Soc. 2024 Oct 30;146(43):29621-29629. doi: 10.1021/jacs.4c10082. Epub 2024 Oct 17.
Biochemical acyl transfer cascades, such as those initiated by the adenylation of carboxylic acids, are central to various biological processes, including protein synthesis and fatty acid metabolism. Designing cascade reactions in aqueous media remains challenging due to the need to control multiple, sequential reactions in a single pot and manage the stability of reactive intermediates. Herein, we developed abiotic cascades using aminoacyl phosphate esters, the synthetic counterparts of biological aminoacyl adenylates, to drive sequential chemical reactions and self-assembly in a single pot. We demonstrated that the structural elements of amino acid side chains (aromatic versus aliphatic) significantly influence the reactivity and half-lives of aminoacyl phosphate esters, ranging from hours to days. This behavior, in turn, affects the number of couplings we can achieve in the network and the self-assembly propensity of activated intermediate structures. The cascades are constructed using bifunctional peptide substrates featuring side chain nucleophiles. Specifically, aromatic amino acids facilitate the formation of transient thioesters, which preorganized into spherical aggregates and further couple into chimeric assemblies composed of esters and thioesters. In contrast, aliphatic amino acids, which lack the ability to form such structures, predominantly undergo hydrolysis, bypassing further transformations after thioester formation. Additionally, in mixtures containing multiple aminoacyl phosphate esters and peptide substrates, we achieved selective product formation by following a distinct pathway that favors subsequent reactions through reactivity changes and self-assembly. By coupling chemical reactions with molecules of varying reactivity time scales, we can drive multiple reaction clocks with distinct lifetimes and self-assembly dynamics, facilitating precise temporal and structural regulation.
生化酰基转移级联反应，如由羧酸的腺苷酸化引发的级联反应，是各种生物过程的核心，包括蛋白质合成和脂肪酸代谢。由于需要在单个容器中控制多个连续反应并管理反应中间体的稳定性，因此在水介质中设计级联反应仍然具有挑战性。在此，我们使用氨酰磷酸酯（生物氨酰腺苷酸的合成对应物）开发了非生物级联反应，以在单个容器中驱动连续化学反应和自组装。我们证明，氨基酸侧链的结构元素（芳香族与脂肪族）显着影响氨酰磷酸酯的反应性和半衰期，范围从数小时到数天。这种行为反过来又影响我们在网络中可以实现的偶联次数以及活化中间体结构的自组装倾向。级联反应使用具有侧链亲核试剂的双功能肽底物构建。具体而言，芳香族氨基酸有利于形成瞬态硫酯，这些硫酯预组织成球形聚集体，并进一步偶联成由酯和硫酯组成的嵌合体组装体。相比之下，缺乏形成此类结构能力的脂肪族氨基酸主要经历水解，在形成硫酯后绕过进一步的转化。此外，在含有多种氨酰磷酸酯和肽底物的混合物中，我们通过遵循有利于通过反应性变化和自组装进行后续反应的独特途径来实现选择性产物形成。通过将化学反应与具有不同反应性时间尺度的分子偶联，我们可以驱动具有不同寿命和自组装动力学的多个反应时钟，从而实现精确的时间和结构调节。
