Comparative study of the effect of dermaseptins S3 and S4 against Cryptococcus neoformans and Aspergillus fumigates

To investigate the structure-function antifungal relationships of two dermaseptins S3 and S4, we assessed the antifungal activity of these dermaseptins and their derivatives against Cryptococcus neoformans and Aspergillus fumigatus. We also determined their haemolytic activity on human red blood cells (RBC). S4 had weak antifungal activity but potent haemolytic activity. Truncated analogs, S4 (1-16) and S4 (1-12), had enhanced potency against the two fungal species and reduced haemolytic activity. Similar behaviour was shown using S3 (1-16) in comparison to native peptide. These results provide indications on how the chain length and charge content affect potency and selectivity.