Amphibian-Derived Antimicrobial Peptides: Essential Components of Innate Immunity and Potential Leads for New Antibiotic Development.

Like other vertebrates, amphibians possess innate and adaptive immune systems. At the center of the adaptive immune system is the Major Histocompatibility Complex. The important molecules of innate immunity are antimicrobial peptides (AMPs). These peptides are secreted by granular glands in the skin and protect the animal against microorganisms entering its body through the skin. AMPs offer an effective and rapid defense against pathogenic microorganisms and have cationic and amphiphilic structures. These peptides are small gene-encoded molecules of 8-50 amino acid residues synthesized by ribosomes. These small molecules typically exhibit activity against bacteria, viruses, fungi, and even cancer cells. It is known that today's amphibian AMPs originated from a common precursor gene 150 million years ago and that the origin of these peptides is preprodermaseptins. Today, antibiotic resistance has occurred due to the incorrect use of antibiotics. Traditional antibiotics are becoming increasingly inadequate. AMPs are considered promising candidates for the development of new-generation antibiotics. Therefore, new antibiotic discoveries are needed. AMPs are suitable molecules for new-generation antibiotics that are both fast and have different killing mechanisms. One of the biggest problems in the clinical applications of AMPs is their poor stability. AMPs generally have limited tropical applications because they are sensitive to protease degradation. Coating these peptides with nanomaterials to make them more stable can solve this problem.