Optogenetic Tools for Minimally Invasive Therapies

1264975Chow将微生物视蛋白泵合理地转换为通道的能力将验证离子通道结构-功能中的一个基本假设，即泵和通道之间的关键区别是是否存在门，该门通过被动电导防止离子回流，并允许针对大梯度的主动离子转移。这项通过蛋白质工程进行合理转化的生物物理壮举将是此类工程中的第一项。此外，虽然已经在文献中评估了质子泵和氯化物泵抑制神经沉默的活性依赖性安全性，但专门用于活性依赖性安全性目的的光遗传试剂的创建是新颖的。此外，设计一种无钙通道的目标实际上与该领域正在进行的努力背道而驰，该领域寻求增加钙电导以提高敏感性。试剂的分子性质是为翻译目的量身定做的，这将代表光遗传试剂开发的一个新方向，到目前为止，该试剂的重点是推动微生物视蛋白的光电流大小、动力学和光谱性质的极限。

1264975ChowThe ability to rationally convert a microbial opsin pump into a channel would validate a fundamental hypothesis in ion channel structure-function, which states that a key difference between a pump and a channel is the existence of a gate that prevents backflow of ions by passive conductance and enables active ion translocation against large gradients. This biophysical feat of rational conversion by protein engineering would be the first of its kind. Furthermore, while the activity-dependent safety of neural silencing by proton and chloride pumps has been evaluated in the literature, the creation of optogenetic reagents specifically for the purpose of activity-dependent safety is novel. Moreover, the translationally focused goal of engineering a calcium-free channelrhodopsin to reduce risk of excito-toxicity is in fact opposite to ongoing efforts in the field, which seek to augment calciumconductance to increase sensitivity. The creation of reagents, whose molecular properties are tailored for translational purposes, would represent a new direction in optogenetic reagent development, which to date have focused on pushing the limits of microbial opsin photocurrent magnitude, kinetics, and spectral properties.