Characterization and Optimization of New CEST Reporter Proteins with Increased Detection Specificity

CEST reporter genes could play a critical role in the optimization of novel biological therapeutics. However, existing amide proton based CEST reporter genes have poor specificity as the amide protons of the reporter gene have the same chemical shift as amide protons from endogenous proteins. Here we report on a new class of reporter proteins with CEST contrast at 5-ppm, based on tyrosine hydroxyl ring protons.