Mechanisms of RyR1 Modulation by General Anesthetics

产品描述： 骨骼肌兰尼碱受体（RyR 1）是细胞钙离子的关键调节因子， 兴奋收缩偶联这种受体的突变是许多严重疾病的基础，其中之一是 这被称为恶性高热（MH）。MH通常在全身麻醉期间意外发生， 并且可能是致命的。麻醉剂调节这种受体的分子内机制，或者即使 它们直接与RyR 1相互作用，这是完全未知的。对于野生型和MH突变体（R615 C） 猪RyR 1，我们将使用光标记技术，以确定是否和在两个挥发性 麻醉剂，异氟烷和七氟烷，结合（目的1）;然后使这些位点与结构相协调， 使用冷冻电子显微镜观察结构变化（目的2）。我们将确定它们的单通道效应 使用平面脂质双层电生理学的离子转运（Aim 3）。最后，我们将测量相对结合亲和力 在预期的多个位点中，哪些位点最有可能与功能效应相关， 复杂的计算方法（平衡分子动力学和炼金术自由能 扰动，目标4）。我们将测试定点突变和天然突变对结合亲和力的影响， 然后将通过目标1和3中的实验反复进行测试。包括初步 数据为每个目标的成功结果提供了信心，并且在 注射全身麻醉剂异丙酚的例子RyR 1是一个具有挑战性的目标，因为它的大小， 复杂性，但技术（光标记，质谱，冷冻电子显微镜，平面 双层电生理学，分子动力学）已经成熟到一个点， campaign有很高的可能性揭示麻醉调节的分子内机制。

Description: The skeletal muscle ryanodine receptor (RyR1) is a critical regulator of cellular calcium to facilitate excitation contraction coupling. Mutations in this receptor underlie a number of serious disorders, one of which is called malignant hyperthermia (MH). MH typically occurs unexpectedly during a general anesthetic, and can be fatal. The intramolecular mechanism by which anesthetics modulate this receptor, or even if they interact directly with RyR1, is completely unknown. For both wild type and MH mutant (R615C) porcine RyR1, we will use photolabeling technology to determine whether and where two volatile anesthetics, isoflurane and sevoflurane, bind (Aim 1); then reconcile these sites with the structure and structural changes using cryo-electron microscopy (Aim 2). We will determine their single-channel effects on ion transit using planar lipid bilayer electrophysiology (Aim 3). Finally, we will gauge relative binding affinity among the expected multiple sites and which of these are most likely to be linked to functional effects, using sophisticated computational approaches (equilibrium molecular dynamics and alchemical free energy perturbation, Aim 4). We will test the effect of site-directed and natural mutations on binding affinity in individual sites, which will then be iteratively tested by experiment in Aims 1 and 3. The included preliminary data lends confidence for a successful outcome in each aim, and also has yielded surprising results in the case of propofol, an injectable general anesthetic. The RyR1 is a challenging target due to its size and complexity, but the technologies (photolabeling, mass spectrometry, cryo-electron microscopy, planar bilayer electrophysiology, molecular dynamics) have matured to a point where this multidisciplinary campaign has a very high probability of revealing the intramolecular mechanism of anesthetic modulation .