Anthrax lethal factor inhibition
Anthrax lethal factor inhibition
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DOI：
10.1073/pnas.0502159102
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发表时间：
2005-05-31
影响因子：
11.1
通讯作者：
Hermes, JD
中科院分区：
文献类型：
--
作者：
Shoop, WL;Xiong, Y;Hermes, JD
炭疽芽孢杆菌的主要毒力因子是一种分泌的锌依赖性金属蛋白酶毒素，被称为致死因子（LF），它通过信号通路的破坏、细胞破坏和循环休克对宿主致命。在活动性炭疽感染期间和感染后立即联合使用抗生素，抑制这种基于蛋白水解的LF毒血症有望提供治疗价值。本文显示了一个亲密配合物的晶体结构之间的羟基，(2R)-2-[（4-氟-3-甲基苯基）磺酰胺]- n-羟基-2-（四氢- 2h -吡喃- 4-基）乙酰胺和LF活性位点的LF。最重要的是，羟肟酸酯和LF活性位点之间的分子相互作用导致(i)在酶分析中抑制LF蛋白酶活性，并在基于细胞的实验中保护巨噬细胞免受重组LF和保护性抗原的攻击，(h)在致命小鼠毒血症模型中对重组LF和保护性抗原具有100%的保护作用。（iii）给予炭疽芽胞杆菌Sterne营养细胞致死攻击的小鼠和给予炭疽芽胞杆菌Ames孢子致死攻击的家兔的生存优势≈50%，两种动物死亡的平均死亡时间均增加一倍；（iv）在兔“不归点”模型中，与环丙沙星联合使用时，对炭疽芽胞杆菌攻击的保护率为100%，而环丙沙星单独提供50%的保护。这些结果表明，一种小分子羟酸酯LF抑制剂，如本文所示，可以改善活动性炭疽杆菌感染的毒血症特征，并可能成为我们对抗炭疽的重要辅助手段。
The primary virulence factor of Bacillus anthracis is a secreted zinc-dependent metalloprotease toxin known as lethal factor (LF) that is lethal to the host through disruption of signaling pathways, cell destruction, and circulatory shock. Inhibition of this proteolytic-based LF toxemia could be expected to provide therapeutic value in combination with an antibiotic during and immediately after an active anthrax infection. Herein is shown the crystal structure of an intimate complex between a hydroxamate, (2R)-2-[(4-fluoro-3-methylphenyl)sulfonylamino]-N-hydroxy-2-(tetrahydro-2H-pyran- 4-yl)acetamide, and LF at the LF-active site. Most importantly, this molecular interaction between the hydroxamate and the LF active site resulted in (i) inhibited LF protease activity in an enzyme assay and protected macrophages against recombinant LF and protective antigen in a cell-based assay, (h) 100% protection in a lethal mouse toxemia model against recombinant LF and protective antigen, (iii) ≈ 50% survival advantage to mice given a lethal challenge of B. anthracis Sterne vegetative cells and to rabbits given a lethal challenge of B. anthracis Ames spores and doubled the mean time to death in those that died in both species, and (iv) 100% protection against B. anthracis spore challenge when used in combination therapy with ciprofloxacin in a rabbit "point of no return" model for which ciprofloxacin alone provided 50% protection. These results indicate that a small molecule, hydroxamate LF inhibitor, as revealed herein, can ameliorate the toxemia characteristic of an active B. anthracis infection and could be a vital adjunct to our ability to combat anthrax.