Terry-Lorenzo Ryan T, Chun Lawrence E, Brown Scott P, Heffernan Michele L R, Fang Q Kevin, Orsini Michael A, Pollegioni Loredano, Hardy Larry W, Spear Kerry L, Large Thomas H
*Discovery Research Department, Sunovion Pharmaceuticals, Marlborough, MA 01752, U.S.A.
†Emerald Bio, Bainbridge Island, WA 98110, U.S.A.
Biosci Rep. 2014 Aug 11;34(4):e00133. doi: 10.1042/BSR20140071.
The NMDAR (N-methyl-D-aspartate receptor) is a central regulator of synaptic plasticity and learning and memory. hDAAO (human D-amino acid oxidase) indirectly reduces NMDAR activity by degrading the NMDAR co-agonist D-serine. Since NMDAR hypofunction is thought to be a foundational defect in schizophrenia, hDAAO inhibitors have potential as treatments for schizophrenia and other nervous system disorders. Here, we sought to identify novel chemicals that inhibit hDAAO activity. We used computational tools to design a focused, purchasable library of compounds. After screening this library for hDAAO inhibition, we identified the structurally novel compound, 'compound 2' [3-(7-hydroxy-2-oxo-4-phenyl-2H-chromen-6-yl)propanoic acid], which displayed low nM hDAAO inhibitory potency (Ki=7 nM). Although the library was expected to enrich for compounds that were competitive for both D-serine and FAD, compound 2 actually was FAD uncompetitive, much like canonical hDAAO inhibitors such as benzoic acid. Compound 2 and an analog were independently co-crystalized with hDAAO. These compounds stabilized a novel conformation of hDAAO in which the active-site lid was in an open position. These results confirm previous hypotheses regarding active-site lid flexibility of mammalian D-amino acid oxidases and could assist in the design of the next generation of hDAAO inhibitors.
N-甲基-D-天冬氨酸受体（NMDAR）是突触可塑性以及学习和记忆的核心调节因子。人D-氨基酸氧化酶（hDAAO）通过降解NMDAR共激动剂D-丝氨酸间接降低NMDAR活性。由于NMDAR功能减退被认为是精神分裂症的一个基本缺陷，hDAAO抑制剂有潜力用于治疗精神分裂症和其他神经系统疾病。在此，我们试图鉴定抑制hDAAO活性的新型化学物质。我们使用计算工具设计了一个集中的、可购买的化合物文库。在筛选该文库的hDAAO抑制活性后，我们鉴定出结构新颖的化合物“化合物2”[3-(7-羟基-2-氧代-4-苯基-2H-色烯-6-基)丙酸]，其显示出低纳摩尔级别的hDAAO抑制效力（Ki = 7 nM）。尽管预期该文库会富集对D-丝氨酸和黄素腺嘌呤二核苷酸（FAD）均具有竞争性的化合物，但化合物2实际上对FAD是非竞争性的，这与苯甲酸等典型的hDAAO抑制剂非常相似。化合物2及其类似物分别与hDAAO进行了共结晶。这些化合物稳定了hDAAO的一种新构象，其中活性位点盖子处于开放位置。这些结果证实了先前关于哺乳动物D-氨基酸氧化酶活性位点盖子灵活性的假设，并有助于下一代hDAAO抑制剂的设计。
