Functional and Structural Characterization of Apidaecin

Drug resistance is a major obstacle to successful antibacterial chemotherapy. With the emergence of antimicrobial-resistant bacterial strains, the current drug families start to fail, and there is an urgent need for alternative agents, preferably with novel modes of action that will prevent bacteria from mounting a quick response and building resistance. Small cationic antimicrobial peptides (AMPs) are evolutionarily ancient components of the host defense system of many different unicellular and pluricel- lular organisms, from bacteria to plants, insects, fish, amphi- bians, birds, and mammals, including humans. 1 In spite of their highly diverse sequences and structural motifs, most of them show a tendency to assume amphiphilic structures in membrane environments. This feature correlates with their ability to perme- able the bacterial membranes, eventually leading to lysis of the microbial cells.