Action mechanism of amphipathic peptides gramicidin S and melittin on erythrocyte membrane.

Amphipathic peptides gramicidin S and melittin caused a characteristic colloid-osmotic hemolysis on human erythrocytes; that is, the peptides produced initially a small membrane lesion in erythrocyte membrane, followed by the release of hemoglobin. The size of membrane lesion increased with an increase in the concentration of peptide. Under the conditions causing membrane lesion, we observed the release of membrane fragments containing phospholipids. The present results show that both the peptides have the ability to stimulate the release of membrane fragments out of the cells and this brings about the perforation of molecules of small size, leading to a colloid-osmotic hemolysis.