SUMO-based expression and purification of dermcidin-derived DCD-1L, a human antimicrobial peptide, in Escherichia coli

The dermcidin-derived peptide DCD-1L has a broad spectrum of antimicrobial activity over a wide pH range and in high salt concentrations. Thus, it offers a promising alternative to conventional antibiotics. Furthermore, it plays a role in wound healing, atopic dermatitis and acne vulgaris, indicating applications in cosmetic industries. Recently, dermcidin has been identified as a tumor marker improving cancer prognosis. Hence, large quantities of purified DCD-1L peptide are required to meet the needs of basic research and clinical trials. In the current study, we demonstrate SUMO-based heterologous DCD-1L production in Escherichia coli, followed by affinity chromatography purification. The SUMO tag is cleaved with SUMO-specific protease following purification, leaving free DCD-1L peptide without any additional amino acids. The mass of the peptide was further confirmed by MALDI-TOF-TOF analysis. Furthermore, the cleaved DCD-1L showed antimicrobial activity against the E. coli DH5 alpha test strain. The production and purification of DCD-1L using SUMO tag compare advantageously to other protocols previously described. Thus, the SUMO tag system enables large scale recombinant production of the antimicrobial peptide DCD-1L, which constitutes pharmaceutical and therapeutic potential as an alternative antibiotic.