Arylazopyrazole-Based Photoswitchable Inhibitors Selective for <i>Escherichia coli</i> Dihydrofolate Reductase
Himadri Sekhar Sarkar, Takato Mashita, Toshiyuki Kowada, Satoshi Hamaguchi, Toshizo Sato, Kento Kasahara, Nobuyuki Matubayasi, Toshitaka Matsui, Shin Mizukami
Abstract
Selective inhibitors of Escherichia coli dihydrofolate reductase (eDHFR) are crucial chemical biology tools that have widespread clinical applications. We developed a set of eDHFR-selective photoswitchable inhibitors by derivatizing the structure of our previously reported methotrexate (MTX) azolog, azoMTX . Substitution of the skeletal p -phenylene group of azoMTX with bulky bis-alkylated arylazopyrazole moieties significantly increased its selectivity toward eDHFR over human DHFR. Owing to the physical properties of arylazopyrazoles, the new ligands exhibited nearly complete Z-to-E photoconversion and high thermostability of Z-isomers. In addition, real-time photoreversible control of eDHFR activity was achieved by alternatively switching the illumination light wavelengths.