Neuropeptidase Function

我们的目标是了解底物识别，催化功能和抑制剂的作用， 神经肽酶、修饰或修饰肽神经递质或神经激素的酶。我们 我建议使用两种相关的神经肽酶，神经溶解素和硫喷妥钠来研究特异性和功能 寡肽酶，作为模型系统。这些锌金属肽酶与神经肽神经降压素结合 并且是精神障碍和疼痛治疗的潜在治疗靶点。他们有一个不寻常的 许多神经肽酶共有的性质。它们在生物活性肽上识别的切割位点 是异常多样的，没有明显的共同特征。这种不寻常的属性和其他属性的基础 酶的功能和抑制方面将通过结合高分辨率结构进行探索 通过酶的功能研究确定。基于先前的工作，我们假设 底物识别主要通过底物肽C末端之间的相互作用发生 和一个不寻常的结合表面，它允许各种不同的肽构象和结合 联系人.我们还认为，铰链样构象变化的酶伴随着催化 一种不寻常的抑制剂C28通过阻止这种运动来破坏酶的功能。四个具体目标 提出了：1）确定与肽和肽类似物复合的酶的晶体结构， 为了使广泛特异性的结构基础可视化，2）通过以下方式测试和改进我们的识别模型： 通过诱变调节酶的特异性，3）检查所提出的 使用速度沉降分析和其他测定4）将我们的研究扩展到嘌呤霉素的C28抑制 敏感的氨肽酶，以评估识别机制的一般性。 与公共卫生的相关性。拟议的研究将提供对酶的理解， 参与控制神经系统中细胞之间的交流。这些酶的知识 将使我们能够操纵它们的活动，以治疗神经系统疾病以及其他疾病。 障碍

Our goal is to understand substrate recognition, catalytic function, and the action of inhibitors in neuropeptidases, enzymes that inactivate or modify peptide neurotransmitters or neurohormones. We propose to study specificity and function using two related neuropeptidases, neurolysin and thimet oligopeptidase, as model systems. These zinc metallopeptidases inactivate the neuropeptide neurotensin and are potential therapeutic targets for psychotic disorders and treatment of pain. They have an unusual property shared by a number of neuropeptidases. The cleavage sites they recognize on bioactive peptides are unusually diverse, with no apparent common features. The basis for this unusual property and other aspects of enzyme function and inhibition will be explored by combining high-resolution structure determination with functional studies of the enzymes. Based on prior work, we hypothesize that broad substrate recognition occurs primarily through the interaction between the C termini of substrate peptides and an unusual binding surface, which allows for a variety of different peptide conformations and binding contacts. We also suggest that a hinge-like conformational change in the enzymes accompanies catalysis and that an unusual inhibitor, C28, disrupts enzyme function by preventing this motion. Four specific aims are proposed: 1) to determine crystal structures of enzymes complexed with peptides and peptide analogs in order to visualize the structural basis for broad specificity, 2) to test and refine our models of recognition by modulating the specificity of the enzyme through mutagenesis, 3) to examine the proposed mechanism of C28 inhibition using velocity sedimentation analysis and other assays 4) to extend our studies to puromycin sensitive aminopeptidase in order to assess the generality of recognition mechanisms. Relevance to public health. The proposed research will provide an understanding of enzymes that are involved in controlling communication between cells in the nervous system. Knowledge of these enzymes will allow us to manipulate their activity in order to treat diseases of the nervous system as well as other disorders