Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
J Am Chem Soc. 2010 Mar 10;132(9):3164-76. doi: 10.1021/ja909996p.
LSD1 is a flavin-dependent histone demethylase that oxidatively removes methyl groups from Lys-4 of histone H3. LSD1 belongs to the amine oxidase enzyme superfamily which utilize molecular oxygen to transform amines to imines that are hydrolytically cleaved to formaldehyde. In prior studies, it has been shown that monoamine oxidase inhibitory scaffolds such as propargylamines and cyclopropylamines can serve as mechanism-based inactivators of LSD1. Propargylamine-histone H3 peptide analogues are potent LSD1 inhibitors, whereas small molecule antidepressant MAO acetylenic inhibitors like pargyline do not inhibit LSD1. In contrast, the small molecule MAO cyclopropylamine inhibitor tranylcypromine is a time-dependent LSD1 inhibitor but exo-cyclopropylamine-peptide substrate analogue is not. To provide further insight into small molecule versus peptide relationships in LSD1 inhibition, herein we further our analysis of warheads in peptide scaffolds to include the chlorovinyl, endo-cyclopropylamine, and hydrazine-functionalities as LSD1 inactivators. We find that chlorovinyl-H3 is a mechanism-based LSD1 inactivator whereas endo-cyclopropylamine-H3 does not show time-dependent inactivation. The hydrazine-H3 was shown to be the most potent LSD1 suicide inhibitor yet reported, more than 20-fold more efficient in inhibiting demethylation than propargylamine-H3 derivatives. We re-explored MAO antidepressant agent phenelzine (phenethylhydrazine), previously reported to be a weak LSD1 inhibitor, and found that it is far more potent than previously appreciated. We show that phenelzine can block histone H3K4Me demethylation in cells, validating it as a pharmacologic tool and potential lead structure for anticancer therapy.
LSD1 是一种黄素依赖的组蛋白去甲基酶，可氧化去除组蛋白 H3 赖氨酸 4 上的甲基。LSD1 属于胺氧化酶酶超家族，该酶利用分子氧将胺转化为亚胺，然后亚胺经水解裂解为甲醛。在先前的研究中，已经表明单胺氧化酶抑制性支架，如炔丙胺和环丙胺，可以作为 LSD1 的基于机制的失活剂。炔丙胺-组蛋白 H3 肽类似物是有效的 LSD1 抑制剂，而小分子抗抑郁药 MAO 炔抑制剂，如帕吉林，不抑制 LSD1。相比之下，小分子 MAO 环丙胺抑制剂反式环丙胺是时间依赖性 LSD1 抑制剂，但外环丙胺-肽底物类似物不是。为了进一步深入了解小分子与肽在 LSD1 抑制中的关系，本文我们进一步分析肽支架中的弹头，包括氯代乙烯基、内环丙胺和肼官能团作为 LSD1 失活剂。我们发现氯代乙烯基-H3 是一种基于机制的 LSD1 失活剂，而内环丙胺-H3 没有表现出时间依赖性失活。肼-H3 被证明是迄今为止报道的最有效的 LSD1 自杀抑制剂，比炔丙胺-H3 衍生物抑制去甲基化的效率高 20 多倍。我们重新研究了 MAO 抗抑郁药苯乙肼（苯乙基肼），先前报道其为弱 LSD1 抑制剂，发现其比以前认为的要强得多。我们表明苯乙肼可以阻断细胞中组蛋白 H3K4Me 的去甲基化，验证了其作为一种药理学工具和潜在的抗癌治疗的先导结构。
