Ion Channel Screening Using Photoswitches

离子通道是一种膜蛋白，它允许带电分子通过细胞膜选择性运动。 膜。许多疾病状态，如囊性纤维化、肌营养不良、高血压和心律失常 是由离子通道病变引起的。离子通道已被药物发现行业确定为优秀的 治疗干预的目标，但由于涉及开发质量，高， 通过功能性离子通道测定，“离子通道药物”的开发一直令人失望。 Photoswitch Biosciences开发了一种技术，可以将小型纳米机器连接到离子通道上 使得能够通过光快速且可逆地控制这些蛋白质。这些“光开关”离子通道允许我们非- 侵入性地控制细胞膜电位，从而控制电压依赖性离子通道的活性。 快速SBIR项目第一阶段的具体目标是：（1）证明以下方面的可行性： 使用细胞外电场记录作为膜电位读出。我们最初的计划是用电压- 敏感染料，但我们实验室最近的结果表明，细胞外记录的电 场电位可提供多种益处，包括仪器设计和分析简单性。第二阶段目标 是建立三个功能齐全的原型筛选系统，包括仪器，工程细胞系， 试剂和软件。采用混合法的细胞外场电位记录技术耦合 与现有技术相比，使用光开关技术进行离子通道测定具有几个优点：（1）消除 用于通道活化的液体添加，（2）用于高通量离子通道药物发现的高度可扩展性，（3） 每个数据点的价格至少比自动电生理学低100倍，（4）通道激活几乎是100倍 比KCl添加更快。以高通量格式快速去重和重定位细胞的能力是 对于发现“使用依赖性”化合物尤其重要， 活跃的渠道。这项突破性的技术将最终允许充分利用离子通道， 药物靶点

Ion channels are membrane proteins that allow the selective movement of charged molecules through cellular membranes. Many disease states, such as cystic fibrosis, muscular dystrophies, hypertension, and cardiac arrhythmias are caused by ion channel pathologies. Ion channels have been identified by the drug discovery industry as excellent targets for therapeutic intervention but because of the technical hurdles involved in developing quality, high- throughput functional ion channel assays, the development of "ion channel drugs" has been disappointing. Photoswitch Biosciences has developed technology, which allows attaching small nanomachines to ion channels enabling rapid and reversible control of these proteins by light. These "photoswitched" ion channels allow us to non- invasively control cell membrane potential and, hence, the activity of voltage-dependent ion channels. The Specific Aim for the Phase I component of this fast track SBIR project are: (1) Demonstrate the feasibility of using extracellular electric field recording as a membrane potential readout. Our original plan was to use voltage- sensitive dyes for this application, but recent results from our lab suggests that extracellular recording of electrical field potentials may offer a variety of benefits, including instrument design and assay simplicity. The Phase II goals are to build three fully functional prototype screening systems consisting of instruments, engineered cell lines, reagents, and software. The use of the hybrid method of extracellular field potential recording technology coupled with photoswitch technology for ion channel assays has several advantages over existing techniques: (1) Elimination of liquid additions for channel activation, (2) Highly scalable for high-throughput ion channel drug discovery, (3) Price per data point is at least 100X less than automated electrophysiology, (4) Channel activation is almost 100X faster than KCl addition. The ability to rapidly depolarize and repolarize cells in a high-throughput format is especially important for the discovery of "use-dependent" compounds that achieve target selectivity via affecting only the channels that are active. This breakthrough technology will finally allow the full exploitation of ion channels as drug targets.