Several protease IV enzymes are widely used in proteomic research. Specifically, protease IV from Pseudomonas aeruginosa has lysyl endopeptidase activity. Here, we report the recombinant expression, refolding, activation, and purification of this protease in Escherichia coli. Proteolytic instability of the activated intermediate, a major obstacle for efficient production, is controlled through ammonium sulfate precipitation. The purified protease IV exhibits superior lysyl endopeptidase activity compared to a commercial product.
Keywords: Activity; Protease IV; Pseudomonas aeruginosa; Purification; Recombinant expression; Refolding.
Copyright © 2016. Published by Elsevier Inc.