Toxoplasma gondii cyclic GMP-dependent kinase:: Chemotherapeutic targeting of an essential parasite protein kinase
Toxoplasma gondii cyclic GMP-dependent kinase:: Chemotherapeutic targeting of an essential parasite protein kinase
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DOI：
10.1128/ec.1.3.317-328.2002
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发表时间：
2002-06-01
期刊：
影响因子：
--
通讯作者：
Liberator, PA
中科院分区：
文献类型：
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作者：
Donald, RGK;Allocco, J;Liberator, PA
三取代的吡咯4-[2-（4-氟苯基）-5-（1-甲基哌啶-4-基）-1H-吡咯-3-基]吡啶（化合物1）在动物模型中对顶复门寄生虫弓形虫和柔嫩艾美耳球虫具有体内活性。推测该化合物在大肠杆菌中的分子靶位。tenella是环GMP依赖性蛋白激酶（PKG）。从T. gondii的动力学和药理学特性与E. tenella同源物，并且两者都已在T.刚地。寄生虫PKG的计算机建模用于预测与化合物1相互作用的催化位点氨基酸残基。实验室产生的重组突变体T. gondii PKG T761 Q或T761 M及类似物E. tenella T770等位基因对化合物1具有降低的结合亲和力，并且不被化合物1抑制。通过所有其他标准，具有这类催化位点取代的PKG与野生型酶是不可区分的。T.只有当PKG的互补拷贝以反式提供时，才能获得弓形虫PKG，这表明PKG是一种必需蛋白。木霉菌株gondii，在基因组PKG位点被破坏，并且依赖于T.弓形虫T761取代的PKG在小鼠中与野生型一样毒力。然而，与感染野生型T.感染实验室产生的弓形虫株的小鼠;弓形虫对治疗没有反应。我们得出结论，PKG代表负责化合物1的抗寄生虫功效的主要分子靶标。
The trisubstituted pyrrole 4-[2-(4-fluorophenyl)-5-(1-methylpiperidine-4-yl)-1H-pyrrol-3-yl]pyridine (compound 1) has in vivo activity against the apicomplexan parasites Toxoplasma gondii and Eimeria tenella in animal models. The presumptive molecular target of this compound in E. tenella is cyclic GMP-dependent protein kinase (PKG). Native PKG purified from T. gondii has kinetic and pharmacologic properties similar to those of the E. tenella homologue, and both have been functionally expressed as recombinant proteins in T. gondii. Computer modeling of parasite PKG was used to predict catalytic site amino acid residues that interact with compound 1. The recombinant laboratory-generated mutants T. gondii PKG T761Q or T761M and the analogous E. tenella T770 allelles have reduced binding affinity for, and are not inhibited by, compound 1. By all other criteria, PKG with this class of catalytic site substitution is indistinguishable from wild-type enzyme. A genetic disruption of T. gondii PKG can only be achieved if a complementing copy of PKG is provided in trans, arguing that PKG is an essential protein. Strains of T. gondii, disrupted at the genomic PKG locus and dependent upon the T. gondii T761-substituted PKGs, are as virulent as wild type in mice. However, unlike mice infected with wild-type T. gondii that are cured by compound 1, mice infected with the laboratory-generated strains of T. gondii do not respond to treatment. We conclude that PKG represents the primary molecular target responsible for the antiparasitic efficacy of compound 1.