Ion Channel Screening Using Photoswitches

描述（由申请人提供）：离子通道是允许带电分子通过细胞膜选择性运动的膜蛋白。许多疾病状态，如囊性纤维化、肌肉营养不良、高血压和心律失常都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治疗干预的优秀靶点，但由于开发高质量、高通量功能离子通道试验所涉及的技术障碍，“离子通道药物”的开发一直令人失望。光开关生物科学公司已经开发出一种技术，可以将小型纳米机器连接到离子通道上，从而通过光对这些蛋白质进行快速可逆的控制。这些“光电开关”离子通道使我们能够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。这个快速通道SBIR项目第一阶段的具体目标是：(1)证明使用细胞外电场记录作为膜电位的可行性

DESCRIPTION (provided by applicant): 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 offera 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.