Sunday, November 8, 2020

An Untargeted Approach for Revealing Electrophilic Metabolites

Yan Yu, Henry H. Le, Brian J. Curtis, Chester J. J. Wrobel, Bingsen Zhang, Danielle N. Maxwell, Judy Y. Pan, and Frank C. Schroeder

ACS Chemical Biology 2020

DOI: 10.1021/acschembio.0c00706

Reactive electrophilic intermediates such as coenzyme A esters play central roles in metabolism but are difficult to detect with conventional strategies. Here, we introduce hydroxylamine-based stable isotope labeling to convert reactive electrophilic intermediates into stable derivatives that are easily detectable via LC–MS. In the model system Caenorhabditis elegans, parallel treatment with 14NH2OH and 15NH2OH revealed >1000 labeled metabolites, e.g., derived from peptide, fatty acid, and ascaroside pheromone biosyntheses. Results from NH2OH treatment of a pheromone biosynthesis mutant, acox-1.1, suggested upregulation of thioesterase activity, which was confirmed by gene expression analysis. The upregulated thioesterase contributes to the biosynthesis of a specific subset of ascarosides, determining the balance of dispersal and attractive signals. These results demonstrate the utility of NH2OH labeling for investigating complex biosynthetic networks. Initial results with Aspergillus and human cell lines indicate applicability toward uncovering reactive metabolomes in diverse living systems.



Lysine-Targeted Covalent Inhibitors of PI3Kδ Synthesis and Screening by In Situ Interaction Upgradation

Bo Yuan, Yifan Feng, Mengyan Ma, Weiming Duan, Yujie Wu, Jiaxin Liu, Hong-Yi Zhao, Zhe Yang, San-Qi Zhang, and Minhang Xin Journal of Medici...