Development of Optical Tools to Control Biological Processes

Optical control of protein function has garnered considerable interest in chemical biology. The use of light to modulate protein function allows for higher spatial and temporal control than small molecule control. Rapamycin is a natural product that can be used to induce the dimerization of FKBP and FRB proteins and has been used as a small molecule to control a wide range of dimerization-based protein functions. We synthesized several light sensitive analogs of rapamycin to allow for optical control of protein dimerization. A visible light-activated rapamycin analog was synthesized and its ability to effectively photocage rapamycin in vivo was demonstrated. A light-deactivated rapamycin analog was synthesized through the conjugation of a reactive oxygen species generating chromophore to rapamycin in an adaption of chromophore-assisted light inactivation of proteins. The ability of this conjugate to reverse protein dimerization was demonstrated in vivo as well. Several analogs of rapamycin conjugated to arylazopyrazole and spiropyran photoswitches were synthesized and the difference in dimerization activity of the two states was determined. Optical control of protein function was also explored through the incorporation of photoswitching amino acids through unnatural amino acid mutagenesis. Two novel photoswitching amino acids containing arylazopyrazole and phenazopyridine photoswitches were synthesized, and incorporation in proteins was demonstrated. Optically active materials have been a focus of researchers developing robotics, information storage methods, and light-activated drug delivery. Commonly, azobenzene is used in these materials. We synthesized an arylazopyrazole-containing monomer capable of being incorporated into a polymer. Analysis of that polymer showed an unexpectedly lesser macroscopic response to irradiation than an azobenzene containing material