ENHANCING ANTIBACTERIAL ACTIVITY AGAINST Escherichia coli K 12 OF PEPTIDE Ib-AMP4 WITH SYNTHETIC ANALOGUES

JOHANNA M. FLÓREZ-CASTILLO; MERCEDES PERULLINI; MATIAS JOBBÁGY; HERMINSUL DE JESÚS CANO CALLE

INTERNATIONAL JOURNAL OF PEPTIDE RESEARCH AND THERAPEUTICS

SPRINGER

Lugar: Berlin; Año: 2014 vol. 20 p. 365 - 369

1573-3149

A family of Ib AMP4 peptide analogues was obtained by solid phase synthesis, modifying the net charge and hydrophobicity of C-terminal domain by replacing certain amino acidic residues by arginine and tryptophan. Additionally, disulfide bonds were eliminated by replacing the cysteine residues by methionine, which resulted in a decrease in the number of synthesis byproducts, and consequently diminished the subsequent purification steps. The obtained peptides were purified by RP HPLC and their molecular mass was determined by MALDI-TOF mass spectrometry. The peptide analogues (IC50 between 1-50 µM) presented a higher antibacterial activity against Escherichia coli K 12 than the native peptide (IC50 > 100 µM). The hemolytic activity of the peptide with the highest antibacterial efficacy presented no degradation of erythrocytes for a concentration of 1 µM that corresponds to its IC50 value. The results show that the synthesized peptides are good candidates for the treatment of diseases caused by Escherichia coli.