Mutations in leucine-rich repeat kinase 2 (LRRK2), such as G2019S, are associated with an increased risk of developing Parkinson’s disease. Surrogates for the LRRK2 kinase domain based on checkpoint kinase 1 (CHK1) mutants were designed, expressed in insect cells infected with baculovirus, purified, and crystallized. X-ray structures of the surrogates complexed with known LRRK2 inhibitors rationalized compound potency and selectivity. The CHK1 10-point mutant was preferred, following assessment of surrogate binding affinity with LRRK2 inhibitors. Fragment hit-derived arylpyrrolo[2,3-b]pyridine LRRK2 inhibitors underwent structure-guided optimization using this crystallographic surrogate. LRRK2-pSer935 HEK293 IC₅₀ data for 22 were consistent with binding to Ala2016 in LRRK2 (equivalent to Ala147 in CHK1 10-point mutant structure). Compound 22 was shown to be potent, moderately selective, orally available, and brain-penetrant in wild-type mice, and confirmation of target engagement was demonstrated, with LRRK2-pSer935 IC₅₀ values for 22 in mouse brain and kidney being 1.3 and 5 nM, respectively.

中文翻译：

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使用源自检查点激酶1（CHK1）的晶体学替代品设计富亮氨酸重复激酶2（LRRK2）抑制剂。

富含亮氨酸的重复激酶2（LRRK2）的突变（例如G2019S）与患帕金森氏病的风险增加相关。设计了基于检查点激酶1（CHK1）突变体的LRRK2激酶结构域的替代物，在杆状病毒感染的昆虫细胞中表达，纯化和结晶。与已知的LRRK2抑制剂配合的替代物的X射线结构可合理化化合物的效价和选择性。在评估与LRRK2抑制剂的替代结合亲和力后，首选CHK1 10点突变体。碎片命中的芳基吡咯并[2,3- b ]吡啶LRRK2抑制剂使用此晶体学替代品进行结构指导的优化。LRRK2-pSer935 HEK293 IC ₅₀数据22与LRRK2中与Ala2016的结合一致（相当于CHK1 10点突变体结构中的Ala147）。化合物22在野生型小鼠中显示有效，适度选择性，口服且对大脑有渗透作用，并证实了靶标参与，小鼠大脑和肾脏中22的LRRK2-pSer935 IC ₅₀值为1.3和5分别为nM。