PROTEIN PHOSPHORYLATION, EPILEPSY & ANTICONVULSANTS

本实验室的研究表明苯妥英， 和苯二氮卓类（BZ）抑制Ca++钙调蛋白 调节蛋白质磷酸化和神经递质释放， 突触准备 根据这些结果提出了一个假设 说明Ca++调节特定脑蛋白的磷酸化， 尤其是在突触处，可能在调节 神经元兴奋性和特定抗惊厥药物的作用。 本研究将系统地检验这一假设。 初始 研究将针对分离Ca++钙调蛋白激酶系统， 表征Ca++、钙调蛋白和抗惊厥药的作用 化合物对蛋白质磷酸化，神经递质释放， Ca++在各种突触制备中调节功能。 我们将 将几种苯并二氮杂卓衍生物抑制 这些Ca++调节事件具有抑制最大的 电击引起抽搐。 该实验室的结果显示， 在脑细胞膜上发现了一个新的抗惊厥药物结合位点。 的 苯二氮卓类药物与该位点结合的效力非常相关 显著地具有抑制最大电击诱导的能力 癫痫发作和Ca++钙调蛋白激酶活性。 这些结果提供 脑内存在抗惊厥药物结合位点的证据 可能调节Ca++钙调蛋白激酶活性的膜 调节突触膜的兴奋性。 采用 高纯度Ca ~（++）钙调蛋白的光亲和标记实验 激酶和膜组分，我们将能够确定是否一个亚基或 激酶系统的调节剂是膜抗惊厥剂的一部分 结合位点 还将启动研究， 最近从大脑中分离出来，是一种有效的Ca++抑制剂 钙调蛋白激酶系统 我们的初步研究表明， 化合物也是一种有效的抗惊厥剂， 休克引起的癫痫 拟议中的实验将使我们能够 表征这种新的内源性抗惊厥物质，并确定 它是一种在癫痫发作时从大脑中释放的“天然”抗惊厥剂 活动，从而抑制癫痫发作活动。

Studies from this laboratory have demonstrated that phenytoin, crbamazepine, and the benzodiazepines (BZ) inhibit Ca++ calmodulin regulated protein phosphorylation and neurotransmitter release in several synaptic preparations. An hypothesis was proposed from these results stating that the Ca++regulated phosphorylation of specific brain proteins, especially at the synapse, may play an important role in regulating neuronal excitability and the action of specific anticonvulsant drugs. This investigation will systematically examine this hypothesis. Initial studies will be directed at isolating the Ca++ calmodulin kinase system and characterizing the effects of Ca++, calmodulin, and anticonvulsant compounds on protein phosphorylation, neurotransmitter release, and Ca++regulated functions in various synaptic preparations. We will correlate the potency of several benzodiazepine derivatives to inhibit these Ca++ regulated events with their potency for inhibiting maximal electric shock induced convulsions. Results from this laboratory have identified a novel anticonvulsant binding site in brain membrane. The potency of the benzodiazepines to bind to this site correlate very significantly with their ability to inhibit maximal electric shock induced seizures and Ca++ calmodulin kinases activity. These results provide evidence for the existence of an anticonvulsant binding site in brain membrane that may regulate the activity of the Ca++ calmodulin kinase system and modulate the excitability of synaptic membrane. Employing photoaffinity labelling experiments with highly purified Ca++ calmodulin kinase and membrane fractions, we will be able to determine if a subunit or modulator of the kinase system is part of the membrane anticonvulsant binding site. Studies will also be initiated to characterize a compound recently isolated from brain that is a potent inhibitor of the Ca++ calmodulin kinase system. Our preliminary studies indicate that this new compound is also a potent anticonvulsant in inhibiting maximal electric shock induced seizures. The proposed experiments will allow us to characterize this new endogenous anticonvulsant substance and determine if it is a "natural" anticonvulsant released from brain during seizure activity with the resultant suppression of seizure activity.