Combined action of polymyxin B and gramicidin Dubos on Liposomes derived from phospholipids of E. coli

Abstract

Liposomes derived from the total phospholipids of E. coli NCL 8879 strain are susceptible to' polymyxin B. More pronounced disruption occurs in the presence of gramicidin DubQ's. GIamicidin at concentration levels which are ineffective against liposomes. potentiates the disruptive action of polymyxin B on liposomes which contain glycine and chromate as markers. The enhancement by gramicidin of the antimembrane activity of polymyxin B is compared with the potentiation effect seen in vitro with in tact cells.