Volgraf Matthew, Gorostiza Pau, Numano Rika, Kramer Richard H, Isacoff Ehud Y, Trauner Dirk
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Nat Chem Biol. 2006 Jan;2(1):47-52. doi: 10.1038/nchembio756. Epub 2005 Dec 11.
The precise regulation of protein activity is fundamental to life. The allosteric control of an active site by a remote regulatory binding site is a mechanism of regulation found across protein classes, from enzymes to motors to signaling proteins. We describe a general approach for manipulating allosteric control using synthetic optical switches. Our strategy is exemplified by a ligand-gated ion channel of central importance in neuroscience, the ionotropic glutamate receptor (iGluR). Using structure-based design, we have modified its ubiquitous clamshell-type ligand-binding domain to develop a light-activated channel, which we call LiGluR. An agonist is covalently tethered to the protein through an azobenzene moiety, which functions as the optical switch. The agonist is reversibly presented to the binding site upon photoisomerization, initiating clamshell domain closure and concomitant channel gating. Photoswitching occurs on a millisecond timescale, with channel conductances that reflect the photostationary state of the azobenzene at a given wavelength. Our device has potential uses not only in biology but also in bioelectronics and nanotechnology.
蛋白质活性的精确调控是生命的基础。通过远程调节结合位点对活性位点进行别构控制是一种广泛存在于各类蛋白质中的调控机制，从酶到分子马达再到信号蛋白。我们描述了一种使用合成光开关操纵别构控制的通用方法。我们的策略以神经科学中至关重要的配体门控离子通道——离子型谷氨酸受体（iGluR）为例进行说明。通过基于结构的设计，我们对其普遍存在的蛤壳型配体结合结构域进行了修饰，开发出一种光激活通道，我们将其称为LiGluR。一种激动剂通过作为光开关的偶氮苯部分共价连接到蛋白质上。在光异构化时，激动剂可逆地呈现到结合位点，引发蛤壳结构域关闭并伴随通道门控。光开关在毫秒时间尺度上发生，通道电导反映了偶氮苯在给定波长下的光稳态。我们的装置不仅在生物学中，而且在生物电子学和纳米技术中都有潜在用途。
