Fluorescence dequenching assay for the activity of TEV protease.

Tobacco etch virus (TEV) protease is a widely used protease for fusion tag cleavage. Despite its widespread usage, an assay to quickly and easily quantify its activity in laboratory settings is still lacking. Thus, researchers may encounter inefficient cleavage of the desired fusion proteins due to poor activity of a given TEV protease preparation.

Spectroscopic and biochemical characterization of metallo-β-lactamase IMP-1 with dicarboxylic, sulfonyl, and thiol inhibitors.

In an effort to probe the biophysical mechanisms of inhibition for ten previously-reported inhibitors of metallo-β-lactamases (MBL) with MBL IMP-1, equilibrium dialysis, metal analyses coupled with atomic absorption spectroscopy (AAS), native state mass spectrometry (native MS), and ultraviolet-visible spectrophotometry (UV-VIS) were used. 6-(1H-tetrazol-5-yl) picolinic acid (1T5PA), ANT431, D/l-captopril, thiorphan, and tiopronin were shown to form IMP-1/Zn(II)/inhibitor ternary complexes, while dipicolinic acid (DPA) and 4-(3-aminophenyl)pyridine-2,6-dicarboxylic acid (3AP-DPA) stripped some metal from the active site of IMP but also formed ternary complexes. DPA and 3AP-DPA stripped less metal from IMP-1 than from VIM-2 but stripped more metal from IMP-1 than from NDM-1.