TY - JOUR
T1 - The effect of glycine replacement with flexible ω-amino acids on the antimicrobial and haemolytic activity of an amphipathic cyclic heptapeptide
AU - Oddo, Alberto
AU - Nyberg, Nils
AU - Frimodt-Møller, Niels
AU - Thulstrup, Peter Waaben
AU - Hansen, Paul Robert
PY - 2015/9/18
Y1 - 2015/9/18
N2 - Although cyclic peptide structures are usually investigated as highly constrained scaffolds, cyclic antimicrobial peptides of natural origin often feature flexible residues. Hereby we report our findings concerning a structure-activity study conducted on a model sequence by replacing a glycine residue with a variety of flexible residues (i.e. Ω-amino and α,Ω-diamino acids). The resulting library has been tested for antimicrobial activity against a wide range of clinically relevant pathogens as well as for toxicity to red blood cells. Circular dichroism and molecular modelling have been used to study changes in conformation. Increments as high as 16-fold in antimicrobial activity (as effective as lipidation) and 2-fold in haemolytic EC50 values were observed. Interestingly, secondary structures can be stabilized by increasing, rather than decreasing, ring flexibility.
AB - Although cyclic peptide structures are usually investigated as highly constrained scaffolds, cyclic antimicrobial peptides of natural origin often feature flexible residues. Hereby we report our findings concerning a structure-activity study conducted on a model sequence by replacing a glycine residue with a variety of flexible residues (i.e. Ω-amino and α,Ω-diamino acids). The resulting library has been tested for antimicrobial activity against a wide range of clinically relevant pathogens as well as for toxicity to red blood cells. Circular dichroism and molecular modelling have been used to study changes in conformation. Increments as high as 16-fold in antimicrobial activity (as effective as lipidation) and 2-fold in haemolytic EC50 values were observed. Interestingly, secondary structures can be stabilized by increasing, rather than decreasing, ring flexibility.
U2 - 10.1016/j.ejmech.2015.08.028
DO - 10.1016/j.ejmech.2015.08.028
M3 - Journal article
C2 - 26318064
SN - 0223-5234
VL - 102
SP - 574
EP - 581
JO - European Journal of Medicinal Chemistry
JF - European Journal of Medicinal Chemistry
ER -