Characterisation of the PTEN inhibitor VO-OHpic.
Characterisation of the PTEN inhibitor VO-OHpic.
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DOI：
10.1007/s12154-010-0041-7
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发表时间：
2010-10-01
期刊：
影响因子：
--
通讯作者：
Woscholski, Rudiger
中科院分区：
文献类型：
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作者：
Mak, Lok Hang;Vilar, Ramon;Woscholski, Rudiger
PTEN（10号染色体上缺失的磷酸酶和紧张素同源物）是一种磷脂酰肌醇三磷酸3-磷酸酶，可以抵消磷酸肌醇3-激酶，因此被认为是糖尿病和癌症的一个有价值的药物靶点。最近，我们证明了VO-OHpic是一种非常有效的PTEN抑制剂，在体外和体内具有纳米摩尔亲和力。鉴于这种抑制剂对未来药物设计和开发的重要性，其作用模式需要阐明。发现VO-OHpic对重组PTEN的抑制是完全可逆的。K(m)和V（max）都受到VO-OHpic的影响，表明PTEN具有非竞争性抑制作用。测定其抑制常数K（ic）为27±6 nM， K（iu）为45±11 nM。采用人工磷酸酶底物3- o -甲基荧光素磷酸（OMFP）或生理底物磷脂酰肌醇3,4,5-三磷酸（PIP(3)）获得了可比较的参数，表明OMFP是PTEN抑制研究和PTEN药物筛选的合适底物。
PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a phosphatidylinositol triphosphate 3-phosphatase that counteracts phosphoinositide 3-kinases and has subsequently been implied as a valuable drug target for diabetes and cancer. Recently, we demonstrated that VO-OHpic is an extremely potent inhibitor of PTEN with nanomolar affinity in vitro and in vivo. Given the importance of this inhibitor for future drug design and development, its mode of action needed to be elucidated. It was discovered that inhibition of recombinant PTEN by VO-OHpic is fully reversible. Both K(m) and V(max) are affected by VO-OHpic, demonstrating a noncompetitive inhibition of PTEN. The inhibition constants K(ic) and K(iu) were determined to be 27±6 and 45±11 nM, respectively. Using the artificial phosphatase substrate 3-O-methylfluorescein phosphate (OMFP) or the physiological substrate phosphatidylinositol 3,4,5-triphosphate (PIP(3)) comparable parameters were obtained suggesting that OMFP is a suitable substrate for PTEN inhibition studies and PTEN drug screening.