By screening a focused library of kinase inhibitor analogues in a phenotypic co-culture assay for angiogenesis inhibition, we identified an aminotriazine that acts as a cytostatic nanomolar inhibitor. However, this aminotriazine was found to be completely inactive in a whole-kinome profiling assay. To decipher its mechanism of action, we used the online target prediction tool PPB2 (http://ppb2.gdb.tools), which suggested lysophosphatidic acid acyltransferase β (LPAAT-β) as a possible target for this aminotriazine as well as several analogues identified by structure-activity relationship profiling. LPAAT-β inhibition (IC50 ≈15 nm) was confirmed in a biochemical assay and by its effects on cell proliferation in comparison with a known LPAAT-β inhibitor. These experiments illustrate the value of target-prediction tools to guide target identification for phenotypic screening hits and significantly expand the rather limited pharmacology of LPAAT-β inhibitors.

中文翻译：

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使用多药理学浏览器PPB2从表型筛选中鉴定溶血磷脂酸酰基转移酶β（LPAAT-β）为纳摩尔血管生成抑制剂的靶标。

通过在表型共培养测定中筛选激酶抑制剂类似物的聚焦库以抑制血管生成，我们确定了一种氨基三嗪，它可作为一种抑制细胞生长的纳摩尔抑制剂。但是，发现该氨基三嗪在全基因组谱分析中完全没有活性。为了解释其作用机理，我们使用了在线靶标预测工具PPB2（http://ppb2.gdb.tools），该工具建议溶血磷脂酸酰基转移酶β（LPAAT-β）作为该氨基三嗪和其他类似物的可能靶标。通过结构-活动关系分析来识别。与已知的LPAAT-β抑制剂相比，在生化分析中证实了LPAAT-β抑制（IC50≈15 nm），并且抑制了它对细胞增殖的作用。