Production and characterization of recombinant human beta-defensin DEFB120

Public health of human beings is threatened by superbugs. Novel human beta-defensins, which contribute to host defense against pathogen invasion and innate immune protection, might be a potent natural candidate pool for new antibiotic lead screening. In the present work, we successfully expressed and purified a novel human beta-defensin, DEFB120, using the IMPACT-TWIN system in Escherichia coli and identified the purified homogeneous proteins using MALDI-TOF mass spectrometry. Then, we performed the fundamental studies on the structure and biological functions for the DEFB120 peptide. The recombinant DEFB120 peptide showed wide antimicrobial effects against E. coli, Staphylococcus aureus and Candida albicans strains without significant hemolytic activity. Furthermore, the high lipopolysaccharide (LPS)-binding affinity in vitro indicated that DEFB120 might be associated with the inhibition of LPS-induced inflammatory response. These results may pave a way for exploiting the essential physiological functions of DEFB120 and also for the development of natural antibiotic pools.