Structure and Inhibition of the CO2-Sensing Carbonic Anhydrase Can2 from the Pathogenic Fungus Cryptococcus neoformans
Structure and Inhibition of the CO2-Sensing Carbonic Anhydrase Can2 from the Pathogenic Fungus Cryptococcus neoformans
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DOI：
10.1016/j.jmb.2008.11.037
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发表时间：
2009-01-30
影响因子：
5.6
通讯作者：
Steegborn, Clemens
中科院分区：
文献类型：
--
作者：
Schlicker, Christine;Hall, Rebecca A.;Steegborn, Clemens
在致病真菌新型隐球菌中，CO2 传感系统对于在自然环境（类似于 0.03% CO2）中的生存至关重要，并介导在人类宿主中向有毒生长的转变（类似于 5% CO2）。该系统由催化碳酸氢盐形成的碳酸酐酶 (CA) Can2 和真菌、碳酸氢盐刺激的腺苷酸环化酶 Cac1 组成。这些酶对真菌代谢和发病机制的关键作用使其成为抗真菌药物的靶点。在这里，我们证明了 Can2 与白色念珠菌 CA Nce103 的功能相似性，并描述了其生化和结构特征。 Can2的晶体结构表明该酶属于“植物型”β-CA，但携带独特的N端延伸，可以与二聚体的活性位点入口相互作用。我们进一步测试了一组化合物，鉴定了纳摩尔 Can2 抑制剂，并展示了 Can2 与抑制剂和产物类似物乙酸酯的复合物的结构，揭示了与生理配体和抑制剂相互作用的见解。 (C) 2008 Elsevier Ltd。保留所有权利。
In the pathogenic fungus Cryptococcus neoformans, a CO2-sensing system is essential for survival in the natural environment (similar to 0.03% CO2) and mediates the switch to virulent growth in the human host (similar to 5% CO2). This system is composed of the carbonic anhydrase (CA) Can2, which catalyzes formation of bicarbonate, and the fungal, bicarbonate-stimulated adenylyl cyclase Cac1. The critical role of these enzymes for fungal metabolism and pathogenesis identifies them as targets for antifungal drugs. Here, we prove functional similarity of Can2 to the CA Nce103 from Candida albicans and describe its biochemical and structural characterization. The crystal structure of Can2 reveals that the enzyme belongs to the "plant-type" beta-CAs but carries a unique N-terminal extension that can interact with the active-site entrance of the dimer. We further tested a panel of compounds, identifying nanomolar Can2 inhibitors, and present the structure of a Can2 complex with the inhibitor and product analog acetate, revealing insights into interactions with physiological ligands and inhibitors. (C) 2008 Elsevier Ltd. All rights resented.