MODIFICATION OF CALMODULIN BY PHENOTHIAZINE DERIVATIVES

钙调素是一种广泛分布的Ca++结合蛋白，它介导了细胞内钙离子的释放， Ca++在各种神经、肌肉和内分泌系统中的作用。 吩噻嗪类抗精神病药物和几种结构相关药物 抑制钙调素的生化作用，通过直接结合到它， Ca++依赖性。 然而，尽管这一点具有潜在的重要性， 在解释吩噻嗪的药理学或 提供了一种新的钙离子调控手段， 依赖过程，对特定的 这种相互作用发生的分子机制。 总 拟议工作的目标是阐明基本机制， 吩噻嗪和相关药物与钙调蛋白结合并抑制 其活动。 具体来说，我计划：1。检查结构活性 选择的吩噻嗪衍生物在预防 钙调素诱导的磷酸二酯酶活化，并确定 疏水键和离子键在这种相互作用中的相对重要性。 2.使用最新开发的技术诱导不可逆结合 用于直接鉴定药物结合位点的吩噻嗪与钙调蛋白的结合 关于钙调素 3.测定吩噻嗪类药物对 钙调素与靶酶相互作用， 膜。 4.检查药物和蛋白质的特异性， 吩噻嗪类化合物对钙调蛋白的光亲和标记 5.确定 吩噻嗪和相关药物是否可以被代谢活化， 在体内与钙调素不可逆地结合。 这些研究的结果应 提供了重要的新的见解的机制，药物可以 改变钙调素的活性，并可能提出新的方法， 调节各种Ca++依赖性过程。

Calmodulin is a widely-distributed Ca++ binding protein that mediates the effects of Ca++ in a variety of neural, muscular and endocrine systems. Phenothiazine antipsychotics and several structurally related agents inhibit the biochemical actions of calmodulin by binding directly to it in a Ca++ dependent manner. However, despite the potential importance of this interaction in explaining the pharmacology of the phenothiazines or in providing a novel means of pharmacologically regulating various Ca++ dependent processes, relatively little is known about the specific molecular mechanisms through which this interaction occurs. The general objective of the proposed work is to elucidate the basic mechanisms by which the phenothiazines and related drugs bind to calmodulin and inhibit its activity. Specifically I plan to: 1. Examine the structure-active relationships of selected phenothiazine derivatives in preventing the calmodulin-induced activation of phosphodiestease and to determine the relative importance of hydrophobic and ionic bonding in this interaction. 2. Use recently developed techniques for inducing the irreversible binding of phenothiazines to calmodulin for directly identifying drug binding sites on calmodulin. 3. Determine the effects of phenothiazines on the ability of calmodulin to interact with target enzymes that are bound to biological membranes. 4. Examine the drug and protein specificities of the photoaffinity labeling of calmodulin by phenothiazines. 5. Determine whether phenothiazines and related drugs can be metabolically activated to bind irreversibly to calmodulin in vivo. Results of these studies should provide important new insights into the mechanisms by which drugs can modify the activity of calmodulin and may suggest new ways of pharmacologically modifying various Ca++ dependent processes.