Improvements in large-scale production of tobacco etch virus protease

Tobacco-etch-virus (TEV) protease is the workhorse of many laboratories in which protein expression is the linchpin of downstream experiments. TEV protease is remarkable in its sequence specificity as the cleavage sequence rarely appears in higher organisms and its ability to cleave fusion tag proteins from proteins of interest. Herein we report work done on large-scale production of TEV protease using different promotors, media, fusion tags, and expression platforms. During our work we detected post-translational modification (gluconoylation and phosphogluconoylation) of TEV protease and the subsequent effects this has on the purity of the protein. Subsequently we made our pgl plus bacteria that negates these modifications and their effects. We also introduce a GFP-based assay for measurement of activity and ultimately a new set of protocols for producing 400-500 mg/L TEV protease.