Selective Inhibition of Neuronal Nitric Oxide Synthase

描述（由申请人提供）：一氧化氮合酶（NOS）是产生一氧化氮的酶家族，用于调节血压、免疫系统功能以及大脑发育、记忆和学习。在病理条件下，产生过量的一氧化氮，这可能导致组织损伤，导致神经退行性疾病。抑制神经元型一氧化氮合酶的广泛目的是开发帕金森病、阿尔茨海默病、亨廷顿病、中风和脑瘫中神经变性的治疗。选择性抑制NOS神经元同工酶对预防高血压和干扰免疫防御系统具有重要意义。下一个预算期的具体目标已从本提案最后一个版本中提出的七个精简为五个，强调增强型nNOS选择性抑制剂的设计，合成，效力和生物利用度。将提出方法，以提高效力，选择性和他们的能力，通过血脑屏障。然而，第一个具体的目标，集中在一类NOS灭活剂相关的机械问题。本论文拟开展的研究工作包括以下五个方面：（1）脒类和取代精氨酸类失活剂对一氧化氮合酶的失活机制研究。(2)将进行并合成我们从计算机建模获得的最有效和最具选择性的新系列化合物的类似物的基于结构的从头设计。(3)将基于人nNOS到大鼠nNOS晶体结构中的同源建模和大鼠与人nNOS中关键残基差异的定点诱变来设计人nNOS的选择性nNOS抑制剂。同源性模型将得到使用人类和低等动物一氧化氮合酶的抑制研究的支持。一位合作者正试图获得人类一氧化氮合酶的晶体结构。(4)新型的神经元型一氧化氮合酶亚基二聚化抑制剂将被设计和合成。(5)将进行各种生物利用度研究，包括体内研究以确定我们的选择性抑制剂是否穿过血脑屏障;化合物与微粒体的稳定性研究; Caco-2细胞渗透性研究; P-糖蛋白外排转运蛋白的底物活性研究。将合成前药类似物以增加生物利用度。

DESCRIPTION (provided by applicant): Nitric oxide synthase (NOS) is a family of enzymes that produces nitric oxide for use in regulating blood pressure, in immune system functioning, and in brain development, memory, and learning. Under pathological conditions, excess nitric oxide is produced, which can result in damage to tissues, leading to neurodegenerative diseases. The broad objective of inhibition of neuronal nitric oxide synthase is the development of a treatment for neurodegeneration in Parkinson's disease, Alzheimer's disease, Huntington's disease, stroke, and cerebral palsy. Selective inhibition of the neuronal isozyme of NOS is important to prevent hypertension and interference with the immune defense system. The specific aims for the next budget period have been streamlined from the seven proposed in the last version of this proposal to five, which emphasize the design, synthesis, potency, and bioavailability of enhanced nNOS-selective inhibitors. Approaches will be presented to increase potency, selectivity, and their ability to cross the blood-brain barrier. The first specific aim, however, focuses on a mechanistic question related to a class of NOS inactivators. The five areas of proposed research are as follows: (1) Studies will be carried out on the mechanisms of inactivation of nitric oxide synthase by amidine and substituted arginine inactivators. (2) Structure-based de novo design of analogues of our most potent and selective new series of compounds obtained from computer modeling will be carried out and synthesized. (3) Selective nNOS inhibitors for human nNOS will be designed based on homology modeling of human nNOS into the crystal structure of rat nNOS and on site-directed mutagenesis of a key residue difference in rat versus human nNOS. The homology model will be supported by inhibition studies using human and lower animal nitric oxide synthases. Attempts at obtaining a crystal structure of human nitric oxide synthases are being made by a collaborator. (4) Novel subunit dimerization inhibitors of neuronal nitric oxide synthase will be designed and synthesized. (5) Various bioavailability studies will be carried out, including in vivo studies to determine if our selective inhibitors cross the blood-brain barrier; stability studies of the compounds with microsomes; Caco-2 cell permeability studies; substrate activity studies for the P-glycoprotein efflux transporter. Prodrug analogues will be synthesized to increase bioavailability.