Open AccessChain length heterogeneity of lipopolysaccharide released from Salmonella typhimurium by ethylenediaminetetraacetic acid or polycations
Author(s) -
HUKARI Ritva,
HELANDER Ilkka M.,
VAARA Martti
Publication year - 1986
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1986.tb09450.x
Subject(s) - lipopolysaccharide , ethylenediaminetetraacetic acid , chemistry , population , galactose , biochemistry , chromatography , membrane , bacterial outer membrane , biology , escherichia coli , organic chemistry , immunology , chelation , sociology , gene , demography
Cells of two smooth Salmonella typhimurium strains (SL696 and SH4247) were treated with ethylenediaminetetraacetic acid (EDTA) and the polycations poly(L‐lysine) and protamine to monitor both quantitatively and qualitatively the release of [ 14 C] galactose‐labelled lipopolysaccharide into the medium to find out whether these effector substances caused selective release of certain fractions from the initially heterogenous lipopolysaccharide population. Each one of the substances released considerable amounts of lipopolysaccharide into the medium. Analysis by sodium dodecyl sulphate/polyacrylamide gel electrophoresis followed by autoradiography showed that the total lipopolysaccharide (from isolated membranes) and the released materials produced coincident banding patterns, each with a high degree of O side‐chain length heterogeneity. Densitometric scans of the autoradiograms were analyzed for possible differences in the distribution and relative abundance of lipopolysaccharide molecules with different O chain lengths. It was found that in SL696 the released materials were identical to the total lipopolysaccharide; in SH4247 subtle deviations from the total lipopolysaccharide were seen. We conclude from these results that lipopolysaccharide molecules with short and long O side chains are linked to and stabilized in the outer membrane by similar mechanisms equally susceptible to the effects of EDTA and polycations.