Enhanced Antimicrobial Activity of AamAP1-Lysine, a Novel Synthetic Peptide Analog Derived from the Scorpion Venom Peptide AamAP1

Abstract

There is great interest in the development of antimicrobial peptides as a potentially novel class of antimicrobial agents. Several structural determinants are responsible for the antimicrobial and cytolytic activity of antimicrobial peptides. In our study, a new synthetic peptide analog, AamAP1-Lysine from the naturally occurring scorpion venom antimicrobial peptide AamAP1, was designed by modifying the parent peptide in order to increase the positive charge and optimize other physico-chemical parameters involved in antimicrobial activity. AamAP1-Lysine displayed potent antibacterial activity against Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration was in the range of 5 to 15 µM with a 10 fold increase in potency over the parent peptide. The hemolytic and antiproliferative activity of AamAP1-Lysine against eukaryotic mammalian cells was minimal at the concentration range needed to inhibit bacterial growth. The antibacterial mechanism analysis indicated that AamAP1-Lysine is probably inducing bacterial cell death through membrane damage and permeabilization determined by the release of β-galactosidase enzyme from peptide treated E. coli cells. DNA binding studies revealed that AamAP1-Lysine caused complete retardation of DNA migration and could display intracellular activities in addition to the membrane permeabilization mode of action reported earlier. In conclusion, AamAP1-Lysine could prove to be a potential candidate for antimicrobial drug development in future studies.

The activity and action mechanism of novel short selective LL‐37‐derived anticancer peptides against clinical isolates of Escherichia coli

“…To provide further insight into potential cell toxicity, we assessed the cytotoxic activity of the peptides against human embryonic kidney 293 (HEK‐293) cells by the colorimetric MTT viability assay for 24 hr, as described earlier . HEK‐293 cells were cultured in RPMI 1640 (supplemented with 10% fetal calf serum, 100 U/ml penicillin and 100 μg/ml streptomycin, 2 mM/L glutamine, and 1 mM sodium pyruvate) in the presence of 5% CO 2 at 37°C.…”

Design and characterization of short hybrid antimicrobial peptides from pEM‐2, mastoparan‐VT1, and mastoparan‐B

“…To determine the in vitro cytotoxicity of peptides, MTT assay was employed . Cultured cells were plated at 10 4 in 96‐well microplate and incubated with various concentrations of each AMP.…”

“…To determine the in vitro cytotoxicity of peptides, MTT assay was employed. [22] Cultured cells were plated at 10 4 in 96-well microplate and incubated with various concentrations of each AMP. Following 6, 12, and 24 h of incubations, cells were incubated with 5 mg/mL 3-(4,5-dimethylthiazol-2 -yl)-2,5-diphenyltetrazolium bromide (MTT, Sigma-Aldrich) for 4 h at 37 °C.…”

Analogs of the Scorpion Venom Peptide Stigmurin: Structural Assessment, Toxicity, and Increased Antimicrobial Activity

“…It is a cationic peptide containing 17 amino acid residues (FFSLIPSLVGGLISAFK-NH 2 ), with +1 net charge and hydrophobic moment of 0.571 [ 13 , 14 ], which presented antimicrobial activity in vitro and in vivo, as well as antiproliferative properties in normal and cancerous cells, with low hemolytic activity [ 13 , 14 ]. The rational design of molecules has been seen to potentiate their activity and biotechnological use; the increase in α-helix, cationic character, and hydrophobic moment can empower the antimicrobial activity [ 15 , 16 , 17 ]. Therefore, two peptide analogs to Stigmurin, denominated as StigA6 (FFSLIPKLVKGLISAFK-NH 2 ) and StigA16 (FFKLIPKLVKGLISAFK-NH 2 ), where serine and glycine were replaced with lysine, were synthesized in order to enhance their antimicrobial and antiproliferative activities.…”