Comparative study of the membrane-permeabilizing activities of mastoparans and related histamine-releasing agents in bacteria, erythrocytes, and mast cells

►Mastoparans and related histamine-releasing agents induce K+ efflux from mast cells, dependent on their ability to cause K+ efflux from bacteria. ►Mastoparans change the normal discoid shape of human erythrocytes to a crenated form at the concentration causing hemolysis. ►The structural requirement for making the crenated form is determined using compound 48/80 and its constituents, changing systematically the number of cationic charges of the molecules.