The article by Michael Zasloff describes the isolation and characterization of a family of antimicrobial peptides, known as magainins, from the skin of the African clawed frog (Xenopus laevis). These peptides are 23 amino acids long and exhibit broad-spectrum antimicrobial activity against bacteria, fungi, and protozoa. They are water-soluble, nonhemolytic, and potentially amphiphilic. The study involved purifying these peptides through a series of chromatographic steps, including ion exchange and gel filtration, and further fractionation by HPLC. The primary sequences of the two most active components, magainin 1 and magainin 2, were determined and found to be distinct but related. The cDNA sequence of a precursor protein was also partially sequenced, revealing that both magainin peptides derive from a larger protein. The magainins are proposed to be a previously unrecognized class of vertebrate antimicrobial peptides, potentially functioning as a host-defense system in the frog's skin. The article discusses the therapeutic potential of these peptides in treating infections in humans.The article by Michael Zasloff describes the isolation and characterization of a family of antimicrobial peptides, known as magainins, from the skin of the African clawed frog (Xenopus laevis). These peptides are 23 amino acids long and exhibit broad-spectrum antimicrobial activity against bacteria, fungi, and protozoa. They are water-soluble, nonhemolytic, and potentially amphiphilic. The study involved purifying these peptides through a series of chromatographic steps, including ion exchange and gel filtration, and further fractionation by HPLC. The primary sequences of the two most active components, magainin 1 and magainin 2, were determined and found to be distinct but related. The cDNA sequence of a precursor protein was also partially sequenced, revealing that both magainin peptides derive from a larger protein. The magainins are proposed to be a previously unrecognized class of vertebrate antimicrobial peptides, potentially functioning as a host-defense system in the frog's skin. The article discusses the therapeutic potential of these peptides in treating infections in humans.