Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nam. 2, 16610 Prague 6, Czech Republic.
J Med Chem. 2014 Oct 23;57(20):8268-79. doi: 10.1021/jm500497v. Epub 2014 Oct 8.
Adenosine kinase (ADK) from Mycobacterium tuberculosis (Mtb) was selected as a target for design of antimycobacterial nucleosides. Screening of 7-(het)aryl-7-deazaadenine ribonucleosides with Mtb and human (h) ADKs and testing with wild-type and drug-resistant Mtb strains identified specific inhibitors of Mtb ADK with micromolar antimycobacterial activity and low cytotoxicity. X-ray structures of complexes of Mtb and hADKs with 7-ethynyl-7-deazaadenosine showed differences in inhibitor interactions in the adenosine binding sites. 1D (1)H STD NMR experiments revealed that these inhibitors are readily accommodated into the ATP and adenosine binding sites of Mtb ADK, whereas they bind preferentially into the adenosine site of hADK. Occupation of the Mtb ADK ATP site with inhibitors and formation of catalytically less competent semiopen conformation of MtbADK after inhibitor binding in the adenosine site explain the lack of phosphorylation of 7-substituted-7-deazaadenosines. Semiempirical quantum mechanical analysis confirmed different affinity of nucleosides for the Mtb ADK adenosine and ATP sites.
结核分枝杆菌（Mycobacterium tuberculosis，Mtb）中的腺苷激酶（Adenosine kinase，ADK）被选为设计抗分枝杆菌核苷的靶标。用 Mtb 和人（h）ADK 对 7-（杂）芳基-7-脱氮腺苷核苷进行筛选，并对野生型和耐药性 Mtb 菌株进行测试，鉴定出对 Mtb ADK 具有微摩尔抗分枝杆菌活性和低细胞毒性的特异性抑制剂。Mtb 和 hADK 与 7-乙炔基-7-脱氮腺苷复合物的 X 射线结构显示，在腺苷结合位点，抑制剂的相互作用存在差异。1D（1）H STD NMR 实验表明，这些抑制剂很容易被容纳到 Mtb ADK 的 ATP 和腺苷结合位点中，而它们优先结合到 hADK 的腺苷位点。抑制剂占据 Mtb ADK 的 ATP 结合位点，以及抑制剂结合到腺苷位点后形成催化能力较弱的半开放构象，解释了 7-取代-7-脱氮腺苷的磷酸化缺失。半经验量子力学分析证实了核苷对 Mtb ADK 腺苷和 ATP 结合位点的不同亲和力。
