PROPERTIES OF A LYSOZYME-DISSOCIATED ENDOTOXIC FRACTION FROM ESCHERICHIA COLI

Publisher Website
Google Scholar
Abstract
Mergenhagen, Stephan E. (National Institute of Dental Research, Bethesda, Md.), and George R. Martin . Properties of a lysozyme-dissociated endotoxic fraction from Escherichia coli . J. Bacteriol. 88: 1169–1174. 1964.—Treatment of a phenol-water preparation of C 14 -labeled Escherichia coli O91–H21 endotoxin of low solubility with lysozyme at pH 5.0 or 8.0 effected a dissociation of the preparation. Such products of dissociation were equally distributed in the chloroform and water phases after extraction. β-Glucosidase, but not β-galactosidase, significantly dissociated this endotoxin also. Concomitant with dissociation, recoverable endotoxin after lysozyme treatment had a reduced content of bound lipid, and dissolved easily in aqueous media to yield a clear solution. Examination of lysozyme-treated endotoxin in an analytical ultracentrifuge revealed that it sedimented as a single major boundary with a sedimentation coefficient of 13.3. Lysozyme-treated endotoxin was more potent than was the conventional endotoxin as evidenced by lethal activity in rabbits and pertussis-sensitized mice. Agar-gel diffusion analysis indicated that the higher molecular weight component associated with conventional endotoxin was dissociated by lysozyme treatment. In immunoelectrophoresis, lysozyme-treated endotoxin was observed as a single sharp band of precipitation which migrated toward the cathode.