Open AccessAntiplasmodial Activity of Lauryl-Lysine Oligomers
Author(s) -
Inna Radzishevsky,
Miriam Krugliak,
Hagaï Ginsburg,
Amram Mor
Publication year - 2007
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.01288-06
Subject(s) - plasmodium falciparum , tetramer , antimicrobial , selectivity , structure–activity relationship , chemistry , antimalarial agent , stereochemistry , peptide , drug , lysine , malaria , biology , biochemistry , amino acid , pharmacology , in vitro , microbiology and biotechnology , enzyme , immunology , catalysis
The ever evolving resistance of the most virulent malaria parasite,Plasmodium falciparum , to antimalarials necessitates the continuous development of new drugs. Our previous analysis of the antimalarial activities of the hemolytic antimicrobial peptides dermaseptins and their acylated derivatives implicated the importance of hydrophobicity and charge for drug action. Following these findings, an oligoacyllysine (OAK) tetramer designed to mimic the characteristics of dermaseptin was synthesized and assessed for its antimalarial activity in cultures ofP. falciparum . The tetramer inhibited the growth of different plasmodial strains at low micromolar concentrations (mean 50% inhibitory concentration [IC50 ], 1.8 μM). A structure-activity relationship study involving eight derivatives unraveled smaller, more potent OAK analogs (IC50 s, 0.08 to 0.14 μM). The most potent analogs were the most selective, with selectivity ratios of 3 orders of magnitude. Selectivity was strongly influenced by the self-assembly properties resulting from interactions between hydrophobic OAKs, as has been observed with conventional antimicrobial peptides. Further investigations performed with a representative OAK revealed that the ring and trophozoite stages of the parasite developmental cycle were equally sensitive to the compound. A shortcoming of the tested compound was the need for long incubation times in order for it to exert its full effect. Nevertheless, the encouraging results obtained in this study regarding the efficiency and selectivity of some compounds establish them as leads for further development.