Structural modification of Escherichia coli lipid A by myristoyltransferase gene from Klebsiella pneumoniae

Abstract

Lipid A in lipopolysaccharide (LPS) of Escherichia coli mutant strains was modified by the introduction of myristoyltransferase gene cloned from Klebsiella pneumoniae. When the gene was introduced into the mutant having lipid A containing only 3-hydroxymyristic acids, it produced lipid A with two additional myristic acids (C14:0). When the same gene was introduced into the mutant with pentaacylated lipid A containing one lauric acid (C12:0), C12:0 was replaced by C14:0. IL-6-inducing activity of LPS with modified lipid A structure suggested that C12:0 in lipid A could be replaced by C14:0 without changing the immunostimulating activity.