以布氏锥虫亮氨酰tRNA合成酶为靶标的抗锥虫药物筛选系统的建立

锥虫是人的血液寄生虫，对热带乃至拉丁美洲贫困地区影响极大，但目前的传统治疗药物存在副作用大、有效性不断降低的问题。根据亮氨酰tRNA合成酶在微生物中可作为药物靶点的事实，在新型抗锥虫药物筛选中，通过对锥虫的亮氨酰tRNA合成酶的克隆、表达和纯化，以及该酶活性测定的优化，建立了该酶抑制物的筛选系统。筛选结果表明，这一以锥虫亮氨酰tRNA合成酶为靶标的抗锥虫药物筛选系统可以有效筛选抗锥虫化合物，选出的化合物有一定的抗锥虫特异性，并可以用于化合物的进一步优化和测定其半抑制浓度。使用这一系统筛选到了对锥虫有较好抑制作用，但对人类细胞毒性较小的一系列新型化合物，因而锥虫亮氨酰tRNA合成酶很可能成为开发有效抗锥虫药物的新靶标。

The Establishment of an Anti-Trypanosoma Drug Screening System with Leucyl-tRNA Synthetase as an Inhibition Target

Trypanosoma is a human parasite severely affecting poor tropical areas. However, current frontline drugs for Trypanosoma treatment have severe side-effects with decreased effectiveness. Based on the fact that aminoacyl-tRNA synthetase is a bonafide drug target for several microorganisms, including bacteria and fungi, it is plausible that it may also be effective target of Trypanosoma. The Trypanosoma brucei leucyl-tRNA synthetase (tbLeuRS) was cloned, expressed and purified to develop an in vitro enzymatic assay system. The assay conditions were further optimized for the effective screening of tbLeuRS inhibitors thus establishing an antiTrypanosoma drug screening system targeting tbLeuRS. The results indicated that this system can be employed for the effective screening of anti-Trypanosoma drugs with satisfactory specificity. In addition, this system can also be used for compound optimization, as well as ICS0 testing. Using this system a series of compounds are identified that are effective Trypanosoma inhibitors without toxicity to human cells. Therefore, targeting tbLeuRS may represent a new venue for the development of anti-Trypanosoma drugs.