Antimicrobial peptide groups such as Cecropins are found widely in animal kingdom. These peptides can permeate the lipid bilayer membranes of most gram-positive and gram-negative bacteria, and cause bacterial cell death, while normal eukaryotic cells are not affected. Recent findings show that they are also able to lyse cancer cells with few toxic effects on normal erythrocytes. ₅₀...[ Read more ]

Antimicrobial peptide groups such as Cecropins are found widely in animal kingdom. These peptides can permeate the lipid bilayer membranes of most gram-positive and gram-negative bacteria, and cause bacterial cell death, while normal eukaryotic cells are not affected. Recent findings show that they are also able to lyse cancer cells with few toxic effects on normal erythrocytes.

Custom lytic peptides, which derived from natural Cecropin B (CB) were designed and synthesized in combination with hydrophobic and amphipathic segments. Circular Dichroism (CD) spectroscopy confirmed that the custom peptides contained secondary structures. Cytotoxicity (MTT) assay was applied to investigate the IC₅₀ values of these peptides on malignant cells including leukemia, stomach carcinoma and breast carcinoma. The results revealed that peptide containing more amphipathic fraction had lower IC₅₀ on various cancer cells. Scanning electron microscopy (SEM) was applied to study the morphological changes of different leukemia cell lines caused by lytic peptides. In addition, surface plasmon resonance (SPR) was used to explore their binding abilities on lipid bilayers and investigate the membrane lysis of liposome. The correlation of peptide sequence with membrane lysing ability was partially obtained throughout these experiments. These studies may be useful for the development of therapeutic peptides for cancer therapy.