Expression of recombinant puroindolines for the treatment of staphylococcal skin infections (acne vulgaris)

Puroindolines are antimicrobial peptides that occur in wheat seed, and are characterized by broad antimicrobial activity. We describe the heterologous expression of puroindoline A and B in the Origami strain of Escherichia coli. The recombinant puroindolines showed the same antimicrobial activity on Staphylococcus epidermidis as compared to the native peptides (MIC90 = 30 μg ml−1). The bactericidal activity was 125 μg ml−1 for recombinant puroindoline A and 42 μg ml−1 for recombinant puroindoline B. Neither protein shows in vitro haemolytic activity or toxicity towards the murine macrophage cell line J774, but they are able to kill intracellular staphylococci. Our preliminary results suggest that recombinant puroindolines deserve further attention as alternatives to the conventional antibiotics in the control of S. epidermidis skin infections.