Photoregulation of -Chymotrypsin Activity by Spiropyran-Based Inhibitors in Solution and Attached to an Optical Fiber

摘要

Here the synthesis and characterization of a new class of spiropyran-based protease inhibitor is reported that can be reversibly photoswitched between an active spiropyran (SP) isomer and a less active merocyanine (MC) isomer upon irradiation with UV and visible light, respectively, both in solution and on a surface of a microstructured optical fiber (MOF). The most potent inhibitor in the series (SP-3b) has a C-terminal phenylalanyl-based -ketoester group and inhibits -chymotrypsin with a K-i of 115nM. An analogue containing a C-terminal Weinreb amide (SP-2d) demonstrated excellent stability and photoswitching in solution and was attached to the surface of a MOF. The SP isomer of Weinreb amide 2d is a competitive reversible inhibitor in solution and also on fiber, while the corresponding MC isomer was significantly less active in both media. The ability of this new class of spiropyran-based protease inhibitor to modulate enzyme activity on a MOF paves the way for sensing applications.