Posts Tagged ‘peptoids’

Reported by: Dr. Venkat S. Karra, Ph.D.

Cationic antimicrobial peptides (CAMPs) are attractive scaffolds for the next generation of antimicrobial compounds, due to their broad spectrum of activity against multi-drug resistant bacteria and the reduced fitness of CAMP-insensitive mutants. Unfortunately, they are limited by poor in vivo performance, including ready cleavage by endogenous serum proteases.

Modified amino acid residues like peptoids are cleavage resistant, and have been recently used in the construction of a number of CAMP derivatives. Peptoid residues are structurally similar to amino acids, but have the R-group transferred from the α-carbon to the amide nitrogen. Lacking the ability to form backbone hydrogen bonds, peptoids do not form standard peptide secondary structures but able to mimic CAMP activity when composed of amphiphilic residues.

Having constructed a series of ultrashort antimicrobial lipopeptides, in the current study they prepared a series of ultrashort amphiphilic peptoids to better understand the effect of the modified backbone.

The activity of the peptoids was assessed against a panel of clinically relevant and laboratory reference bacteria, and the potential for non-specific binding was determined through hemolytic testing and repeating the antimicrobial testing in the presence of added bovine serum albumin (BSA).

The most active peptoids displayed good to moderate activity against most of the Gram positive strains tested and moderate to limited activity against the Gram negatives.

Antimicrobial activity was positively correlated with toxicity towards eukaryotic cells, but was almost completely eliminated by adding BSA.



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