DEVELOPMENT OF UNIFIED MODELS OF CCK RECEPTOR SUBTYPE

本研究的总体目标是使用CCK-B的3D模型， CCK-A肽药效团，先前通过比较母体获得 肽及其肽类似物，以及新开发的3D模型， CCK-B和CCK-A受体本身，以设计非肽激动剂， 可能与CCK-B和CCK-A的相同位点结合的拮抗剂 受体。 我们在这个项目中要遵循的策略是 基于合理的设计。 基于先前CCK的结果 我们会在以下方向扩展未来的研究： (1)我们将使用开发的模型为CCK-B受体结合的 用于非肽激动剂和拮抗剂的合理设计的构象 具有CCK-B选择性。 我们将通过两种收敛的方法来设计这些化合物， 路径：（i）通过刚性化所提出的受体结合构象异构体（因此 进一步完善模型），以及，（ii）通过修改，根据 模型，已知的非肽CCK-B拮抗剂，以获得非肽激动剂 （迄今为止还没有发现CCK-B非肽激动剂）。 这些研究 将开辟先导化合物的途径， 药品水平。 （二）、 我们将进一步完善 CCK-A受体结合构象异构体的分子模拟、合成及结构分析 构象受限的环状化合物的生物学测试。 然后， 该模型可用于CCK-A选择性非肽激动剂的设计 和拮抗剂。 我们还将研究构象关系 肽（激动剂和拮抗剂）和非肽拮抗剂之间 （同样，非肽激动剂是未知的）具有CCK-A选择性。 （三） 我们将进一步发展CCK-B和CCK-A受体的初步三维模型 建议的基础上，独特的计算机程序，可在我们的 实验室 这些程序包括确定跨膜末端的tof 蛋白质序列中的螺旋片段，将这些片段包装在一起， 特殊的分子识别算法，并恢复螺旋间 循环通过残余-残余接触矩阵技术。 (4)我们将使用 获得了CCK-B和CCK-A肽药效团以及CCK-B的模型 和CCK-A受体用于肽和非肽配体的国家设计 两种受体。 我们将合成设计的化合物， 提交它们用于体外生物学研究以及细胞测试系统 与克隆和表达的突变体和嵌合CCK受体。

The general goal of the present study is to use 3D models of the CCK-B and CCK-A peptide pharmacophores, previously obtained by comparison of a parent peptide and its peptide analogs, as well as newly developed 3D models for CCK-B and CCK-A receptors themselves, to design non-peptide agonists and antagonists presumably binding to the same sites of the CCK-B and CCK-A receptors. The strategy we are going to follow in this project will be based on a rational design. Based on the results of the previous CCK project, we will extend the future studies in the following directions: (1) We will use the developed model for the CCK-B receptor-bound conformation for rational design of non-peptide agonists and antagonists with CCK-B selectivity. We will design these compounds by two convergent paths: (i) by rigidifying the proposed receptor-bound conformer (thus refining the model further), and, (ii) by modifying, in accordance with the model, known non-peptide CCK-B antagonists to obtain non-peptide agonists (there is no CCK-B non-peptide agonists discovered so far). These studies will open the route to lead compounds, which could be developed to the level of pharmaceuticals. (2). We will refine further the model of the CCK-A receptor-bound conformer by molecular modeling, synthesis and biological testing of conformationally constrained cyclic compounds. Then, this model will be used for design of CCK-A selective non-peptide agonists and antagonists. We will study also the conformational relationships between peptide (agonists and antagonists) and non-peptide antagonists (again, non-peptide agonists are not known) with CCK-A selectivity. (3) We will develop further the initial 3D models for CCK-B and CCK-A receptors suggested on the basis of the unique computer procedures available in our lab. These procedures include determining tof the ends for transmembrane helical segments in protein sequences, packing these segments together by special molecular recognition algorithm, and restoring the inter helical loops by residue-residue contact matrix technique. (4) We will use the obtained models for CCK-B and CCK-A peptide pharmacophores and for CCK-B and CCK-A receptors for national design of peptide and non-peptide ligands for both receptors. We will synthesize the designed compounds and will submit them for biological studies in vitro as well as in cell test systems with cloned and expressed mutants and chimeric CCK receptors.