Dermaseptin acetate, a peptide isolated from frog skin, exhibits potent antimicrobial activity against bacteria, fungi, and protozoa at micromolar concentration[1].

Dermaseptin acetate is a water-soluble, thermostable, and nonhemolytic peptide endowed with highly potent antimicrobial activity against pathogenic fungi at micromolar concentration. Circular dichroism spectra of Dermaseptin acetate in hydrophobic media indicated 80% alpha-helical conformation, and predictions of secondary structure suggested that Dermaseptin acetate can be configured as an amphiphatic alpha-helix spanning over residues 1-27, a structure that perturbs membrane functions regulating water flux[1]. Dermaseptin acetate exerts a lytic action upon bacteria, protozoa, yeasts, and filamentous fungi at micromolar concentrations. Molecular elements responsible for the exceptional antimicrobial potency of Dermaseptin acetate are to be traced to the NH2-terminal alpha-helical amphipathic segment spanning residues 1-18 of the molecule[1]. Dermaseptin acetate (5-100 μg/ml; 48 hours) inhibits by 100% the proliferation of most microorganisms tested, including Gram-positive or Gram-negative bacteria, parasites, yeasts, and filamentous fungi, at micromolar concentrations[2]. Dermaseptin acetate (5-100 μg/ml; 48 hours) does not inhibit the proliferation of human KJ3 cells after a 48 h incubation, and Dermaseptin acetate treatment for 1 h does not permeate guinea pig lymphocytes up to the highest concentration assayed (200 μg/ml). Hemolysis of rabbit erythrocytes occurrs after 1 h of treatment at doses above 200 μg/ml, with 50% hemolysis at 350 μg/ml[2]. Dermaseptin acetate has antimicrobial activities and is against?Aeromonas cauiae,?Pseudomonas aeroginusa,?Escherichia coli,?Enterococcus faecalis,?L. mezicana?(NFα?strain) and?Microsporum canis?(IP1194) with MIC values of 50 μg/ml; 100 μg/ml; 25 μg/ml; 15 μg/ml; and 50 μg/ml, respectively[2].