Rational development of Stafib-2: a selective, nanomolar inhibitor of the transcription factor STAT5b
Rational development of Stafib-2: a selective, nanomolar inhibitor of the transcription factor STAT5b
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DOI：
10.1038/s41598-017-00920-3
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发表时间：
2017-04-11
影响因子：
4.6
通讯作者：
Berg, Thorsten
中科院分区：
文献类型：
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作者：
Elumalai, Nagarajan;Berg, Angela;Berg, Thorsten
转录因子STAT 5 b是肿瘤治疗的靶点。我们最近报道了儿茶酚二磷酸和衍生物如Stafib-1作为STAT 5 b SH 2结构域的第一选择性抑制剂。在这里，我们通过固态核磁共振证明了儿茶酚二磷酸的STAT 5 b结合，并报告了Stafib-1（Ki = 44 nM）到Stafib-2（Ki = 9 nM）的合理优化。采用等温滴定量热法（ITC）和蛋白质点突变分析相结合的方法对Stafib-2的结合位点进行了验证，这是首次通过ITC对野生型与突变蛋白质进行功能比较，并通过氨基酸解析来表征STAT蛋白质小分子配体的结合位点。前药Pomstafib-2选择性抑制人白血病细胞中STAT 5 b的酪氨酸磷酸化，并以STAT 5依赖性方式诱导细胞凋亡。我们提出Pomstafib-2，这是目前最活跃的，选择性的STAT 5 b激活抑制剂，作为一种化学工具，用于解决不同的STAT 5蛋白在各种细胞过程中发挥作用的基本问题。
The transcription factor STAT5b is a target for tumour therapy. We recently reported catechol bisphosphate and derivatives such as Stafib-1 as the first selective inhibitors of the STAT5b SH2 domain. Here, we demonstrate STAT5b binding of catechol bisphosphate by solid-state nuclear magnetic resonance, and report on rational optimization of Stafib-1 (K-i = 44 nM) to Stafib-2 (K-i = 9 nM). The binding site of Stafib-2 was validated using combined isothermal titration calorimetry (ITC) and protein point mutant analysis, representing the first time that functional comparison of wild-type versus mutant protein by ITC has been used to characterize the binding site of a small-molecule ligand of a STAT protein with amino acid resolution. The prodrug Pomstafib-2 selectively inhibits tyrosine phosphorylation of STAT5b in human leukaemia cells and induces apoptosis in a STAT5-dependent manner. We propose Pomstafib-2, which currently represents the most active, selective inhibitor of STAT5b activation available, as a chemical tool for addressing the fundamental question of which roles the different STAT5 proteins play in various cell processes.