Galloflavin (CAS 568-80-9): A Novel Inhibitor of Lactate Dehydrogenase
Galloflavin (CAS 568-80-9): A Novel Inhibitor of Lactate Dehydrogenase
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DOI：
10.1002/cmdc.201100471
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发表时间：
2012-02-06
期刊：
影响因子：
3.4
通讯作者：
Recanatini, Maurizio
中科院分区：
文献类型：
--
作者：
Manerba, Marcella;Vettraino, Marina;Recanatini, Maurizio
癌细胞最显著的变化之一是它们严格依赖糖酵解途径来产生ATP。这一观察结果导致了糖酵解抑制剂作为潜在抗癌药物的评估。抑制乳酸脱氢酶(LDH)是一种在不影响正常组织能量平衡的情况下抑制肿瘤细胞葡萄糖代谢的有前景的方法。然而，这种方法的成功主要取决于显示出良好选择性的抑制剂的可用性。我们发现了一种化合物(没食子黄素，CAS 568-80-9)，与其他人类LDH抑制剂相比，它既能抑制酶的A亚型，又能抑制B亚型。为了确定作用机制，我们收集了LDH-A和-B在与丙酮酸或NADH竞争反应中的抑制数据，并用酶动力学分析软件对结果进行了评估。我们发现，没食子黄素通过优先结合游离酶而抑制这两种人LDH异构体，而不与底物或辅因子竞争。计算出丙酮酸的KI值分别为：穆穆M(LDH-A)5.46 mM和LDH-B(LDH-B)15.06 mU M。在培养的肿瘤细胞中，没食子黄素在微摩尔浓度下阻止有氧糖酵解，不干扰细胞呼吸，并通过触发细胞凋亡而诱导细胞死亡。据我们所知，到目前为止，对LDH的抑制是对没食子黄素所描述的唯一的生化效应。由于没能在市场上买到没食子黄素，我们在此也描述了它的合成方法，并首次报道了它的完整的化学特征。
One of the most prominent alterations in cancer cells is their strict dependence on the glycolytic pathway for ATP generation. This observation led to the evaluation of glycolysis inhibitors as potential anticancer agents. The inhibition of lactate dehydrogenase (LDH) is a promising way to inhibit tumor cell glucose metabolism without affecting the energetic balance of normal tissues. However, the success of this approach depends chiefly on the availability of inhibitors that display good selectivity. We identified a compound (galloflavin, CAS 568-80-9) which, in contrast to other inhibitors of human LDH, hinders both the A and B isoforms of the enzyme. To determine the mechanism of action, we collected LDH-A and -B inhibition data in competition reactions with pyruvate or NADH and evaluated the results using software for enzyme kinetics analysis. We found that galloflavin inhibits both human LDH isoforms by preferentially binding the free enzyme, without competing with the substrate or cofactor. The calculated Ki values for pyruvate were 5.46 mu mu M (LDH-A) and 15.06 mu M (LDH-B). In cultured tumor cells, galloflavin blocked aerobic glycolysis at micromolar concentrations, did not interfere with cell respiration, and induced cell death by triggering apoptosis. To our knowledge, the inhibition of LDH is, to date, the only biochemical effect described for galloflavin. Because galloflavin is not commercially available, we also describe herein a procedure for its synthesis and report its first full chemical characterization.