Action of mycosubtilin on erythrocytes and artificial membranes.

Mycosubtilin has a strong lytic action upon erythrocytes. The haemolytic effect of the antibiotic is inhibited by free cholesterol as well as cholesterol included in liposomes of phosphatidylcholine-cholesterol. The antibiotic binding on artificial membranes was studied with radioactive bilayer vesicles of dipalmitoylphosphatidylcholine (DPPC), and DPPC-cholesterol:mycosubtilin destroyed both kinds of vesicles. The inhibition of the haemolytic effect of mycosubtilin by liposomes is a result of an interaction which diminishes the concentration of free cholesterol.