Principal Investigator Ronald Raines
The intracellular activity of many enzymes and proteins can be decreased by small-molecule inhibitors or antagonists. Increasing intracellular activity is, however, a much more formidable challenge. In 2007, we introduced the method of “super-charging” -- converting anionic residues into cationic ones so as to enhance uptake into cells (which are anionic). That method is efficient for directing proteins into endosomes but not the cytosol, is often deleterious to protein structure/function, and is not bioreversible, which could lead to immunogenicity.
Now, we are using esterification with diazo compounds to “cloak” anionic carboxylates and thereby to enable protein uptake directly into the cytosol. There, esterases convert the nascent esters back into carboxylates. This novel approach is enabling us to replace dysfunctional proteins, interfere with protein–protein interactions, control stem-cell fate, and edit the genome.