Structure-Guided Synthesis of FK506 and FK520 Analogs with Increased Selectivity Exhibit In Vivo Therapeutic Efficacy against Cryptococcus.
Structure-Guided Synthesis of FK506 and FK520 Analogs with Increased Selectivity Exhibit In Vivo Therapeutic Efficacy against Cryptococcus.
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作者：
钙调神经磷酸酶是一种重要的毒力因子，在人类真菌病原体中保守，包括新型隐球菌、烟曲霉和白色念珠菌。尽管钙调神经磷酸酶是抗真菌药物开发的极好靶标，但其丝氨酸-苏氨酸磷酸酶活性在哺乳动物中是保守的，抑制该活性会导致免疫抑制。 FK506（他克莫司）是一种天然产生的大环化合物，通过与亲免蛋白 FKBP12 结合来抑制钙调神经磷酸酶。此前，我们基于真菌钙调磷酸酶-FK506-FKBP12 结构的方法鉴定了 FKBP12 的一个非保守区域，可用于真菌特异性靶向。这些研究导致了 FK506 类似物 APX879 的设计，该类似物在 C-22 位点进行了修饰，其免疫抑制作用较小，但仍保持抗真菌活性。我们现在报道了真菌 FKBP12 和与天然 FK506 类似物 FK520（子囊霉素）结合的人截短钙调磷酸酶-FKBP12 的高分辨率蛋白质晶体结构。基于这些结构的信息和 APX879 的成功，我们合成并筛选了一组源自 FK506 和 FK520 的新型 C-22 修饰化合物。一种化合物 JH-FK-05 在体外表现出广谱抗真菌活性，并且在体内具有非免疫抑制作用。在肺部和播散性新型隐球菌感染的小鼠模型中，JH-FK-05 单独治疗以及与氟康唑联合治疗可显着降低真菌负荷并延长动物生存期。此外，通过 JH-FK-05 与真菌和人类 FKBP12 结合进行的分子动力学模拟发现了 C-22 和 C-21 位点之外的其他残基，可以对其进行修饰以生成具有改进的抗真菌活性的新型 FK506 类似物。
Calcineurin is an essential virulence factor that is conserved across human fungal pathogens, including Cryptococcus neoformans, Aspergillus fumigatus, and Candida albicans. Although an excellent target for antifungal drug development, the serine-threonine phosphatase activity of calcineurin is conserved in mammals, and inhibition of this activity results in immunosuppression. FK506 (tacrolimus) is a naturally produced macrocyclic compound that inhibits calcineurin by binding to the immunophilin FKBP12. Previously, our fungal calcineurin-FK506-FKBP12 structure-based approaches identified a nonconserved region of FKBP12 that can be exploited for fungus-specific targeting. These studies led to the design of an FK506 analog, APX879, modified at the C-22 position, which was less immunosuppressive yet maintained antifungal activity. We now report high-resolution protein crystal structures of fungal FKBP12 and a human truncated calcineurin-FKBP12 bound to a natural FK506 analog, FK520 (ascomycin). Based on information from these structures and the success of APX879, we synthesized and screened a novel panel of C-22-modified compounds derived from both FK506 and FK520. One compound, JH-FK-05, demonstrates broad-spectrum antifungal activity in vitro and is nonimmunosuppressive in vivo. In murine models of pulmonary and disseminated C. neoformans infection, JH-FK-05 treatment significantly reduced fungal burden and extended animal survival alone and in combination with fluconazole. Furthermore, molecular dynamic simulations performed with JH-FK-05 binding to fungal and human FKBP12 identified additional residues outside the C-22 and C-21 positions that could be modified to generate novel FK506 analogs with improved antifungal activity.
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影响因子：
4.5
作者：
Chow EW;Clancey SA;Billmyre RB;Averette AF;Granek JA;Mieczkowski P;Cardenas ME;Heitman J
通讯作者：
Heitman J
影响因子：
3.4
作者：
Coelho C;Casadevall A
通讯作者：
Casadevall A
影响因子：
2.8
作者：
Grabowski, Marek;Cymborowski, Marcin;Minor, Wladek
通讯作者：
Minor, Wladek
影响因子：
3.3
作者：
HATANAKA, H;IWAMI, M;OKUHARA, M
通讯作者：
OKUHARA, M
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH