Redesigned pMAL expression vector for easy and fast purification of active native antimicrobial peptides

AIMS: The aim of this study was to construct the improved pMAL expression vector to increase the efficacy of purification of small native peptides and their clear-cut separation from MBP tag. The modifications we introduced can be applied to many expression vectors. METHODS AND RESULTS: -enterokinase leaving pure native protein in solution. These new vectors and the two-step purification protocol were successfully applied in purification of active native small antimicrobial peptides (AMPs), lactococcin A and human β-defensin. CONCLUSIONS: We constructed the improved pMAL expression vectors and established the pipeline and optimal conditions for their use in efficient purification of large amounts of active native small peptides. SIGNIFICANCE AND IMPACT OF THE STUDY: Choice of expression vector impacts on the efficiency of expression and purification of desired proteins. The idea of redesigning pMAL vector was driven by the need for rapid purification of larger amounts of active native AMPs. This newly improved pMAL vector, the cloning strategy, expression conditions and two-step purification protocol represent a unique simple approach which can be applied in every laboratory.