Abstract：
Sclerostin is a secreted glycoprotein that expresses predominantly in osteocytes and inhibits bone formation by antagonizing the Wnt/β-catenin signaling pathway, and the loop3 region of sclerostin has recently discovered as a novel therapeutic target for bone anabolic treatment without increasing cardiovascular risk. Herein, we used a structural based virtual screening to search for small molecular inhibitors selectively targeting sclerostin loop3. A novel natural product hit ZINC4228235 (THFA) was identified as the sclerostin loop3-selective inhibitor with a Kd value of 42.43 nM against sclerostin loop3. The simplification and derivation of THFA using molecular modeling-guided modification allowed the discovery of an effective and loop3-selective small molecular inhibitor, compound (4-(3-acetamidoprop-1-yn-1-yl)benzoyl)glycine (AACA), with improved binding affinity (Kd = 15.4 nM) compared to the hit THFA. Further in-vitro experiment revealed that compound AACA could attenuate the suppressive effect of transfected sclerostin on Wnt signaling and bone formation. These results make AACA as a potential candidate for development of anti-osteoporosis agents without increasing cardiovascular risk.
摘要：
硬化蛋白是一种分泌型糖蛋白，主要在骨细胞中表达，通过拮抗Wnt/β-catenin信号通路抑制骨形成，和硬化蛋白的loop3区域最近被发现作为骨合成代谢治疗的一个新的治疗靶点而不增加心血管风险。在这里，我们使用基于结构的虚拟筛选来搜索选择性靶向硬化蛋白loop的小分子抑制剂3.一种新型天然产物命中ZINC4228235(THFA)被鉴定为硬化蛋白环3选择性抑制剂,其针对硬化蛋白环3的Kd值为42.43nM。使用分子建模指导的修饰对THFA进行简化和推导，从而发现了一种有效的环3选择性小分子抑制剂，化合物(4-(3-乙酰氨基丙-1-炔-1-基)苯甲酰基)甘氨酸(AACA)，与命中的THFA相比具有改善的结合亲和力(Kd=15.4nM)。进一步的体外实验表明，化合物AACA可以减弱转染的硬化素对Wnt信号和骨形成的抑制作用。这些结果使AACA成为开发抗骨质疏松症药物而不增加心血管风险的潜在候选者。
