Department of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, La Jolla, California 92037, United States.
Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, Wisconsin 53706, United States.
ACS Infect Dis. 2024 Nov 8;10(11):3744-3750. doi: 10.1021/acsinfecdis.4c00750. Epub 2024 Oct 28.
Botulinum neurotoxin type A (BoNT/A) is an exceptionally potent neurotoxin of great therapeutic value; however, it is also considered a weapon of mass destruction, as it is one of the most poisonous biological substances known to man. The etiology behind BoNT/A is its action as a zinc-dependent protease, which can cause extended paralysis through the cleavage of SNARE proteins. Thiosemicarbazones, known zinc chelators, provide a privileged scaffold that can be leveraged for the development of BoNT/A LC inhibitors. Through a combination of biochemical and kinetic assays, it was demonstrated that the thiosemicarbazone ZMC1, an antitumor agent, is an effective competitive inhibitor of the BoNT/A LC. Based on these results, a series of thiosemicarbazones were designed/synthesized using structure-based analysis and examined in enzyme activity and cell-based assays. From this screen, two analogues presented noteworthy cellular activity. The most potent inhibitors were then tested in a BoNT/A mouse lethality assay, providing statistically significant prolonged survival.
A型肉毒毒素（BoNT/A）是一种具有极高治疗价值的强效神经毒素；然而，它也被认为是一种大规模杀伤性武器，因为它是已知对人类最毒的生物物质之一。BoNT/A 的病因是其作为锌依赖性蛋白酶的作用，该酶可以通过切割 SNARE 蛋白导致长时间瘫痪。硫代氨基甲酸盐，已知的锌螯合剂，提供了一个可以利用的特权支架，可用于开发 BoNT/A LC 抑制剂。通过生化和动力学测定的组合，证明抗肿瘤剂硫代氨基甲酸盐 ZMC1 是 BoNT/A LC 的有效竞争性抑制剂。基于这些结果，使用基于结构的分析设计/合成了一系列硫代氨基甲酸盐，并在酶活性和基于细胞的测定中进行了检查。从该筛选中，两种类似物表现出显著的细胞活性。然后在 BoNT/A 小鼠致死性测定中测试最有效的抑制剂，提供了统计学上显著的延长存活。
