Abstract

Aurein 2.6-COOH and aurein 3.1-COOH
were studied along with their naturally occurring C-terminally
amidated analogues. Circular dichroism (CD) and
molecular dynamic (MD) simulations were used to study
the effects of amidation on the interaction of antimicrobial
peptides (AMPs) with lipid bilayers. CD measurements
and MD analysis suggested that both peptide analogues
were predominantly random coil and adopted low
levels of α-helical structure in solution (<30 %) and in the
presence of a lipid bilayer the peptides formed a stable α
-helical structure. In general, amidated analogues have a
greater propensity than the non-amidated peptides to form
a α-helical structure. MD simulations predicted that aurein
2.6-COOH and aurein 3.1-CHOOH destabilised lipid bilayers
from 1,2-dimyristoyl-sn-glycero-3-phosphocholine and
1,2-dimyristoyl-sn-glycero-3-phosphoserine via angled
bilayer penetration. They also showed that aurein 2.6-
CONH2 and aurein 3.1-CONH2 formed a helix horizontal
to the plane of an asymmetric interface.