Ak. Datta et S. Basu, Chemical characterization of the lipopolysaccharides from enteropathogenicEscherichia coli 0142 and 0158, I J BIOCH B, 36(1), 1999, pp. 55-58
Lipopolysaccharides (LPS) from two enteropathogenic strains of E. coli O142
and O158 were isolated by hot phenol-water extraction procedure. Polyacryl
amide gel electrophoretic pattern of the LPS showed the typical ladder like
pattern of smooth type of LPS. The LPS of E coli O158 was found to contain
L-rhamnose, D-glucose and N-acetyl-D-galactosamine as major constituents t
ogether with D-galactose, N-acetyl-D-glucosamine, L-glycero-D-manno-heptose
and 2-keto-3-deoxy-D-manno-octulosonic acid (KDO) whereas LPS from E: coli
O142 contained L-rhamnose, N-acetyl-D-glucosamine and N-acetyl-D-galactosa
mine as major constituents together with D-glucose, D-galactose, N-acetyl-D
-glucosamine, L-glycero-D-manno-heptose and 2-keto-3-deoxy-D-manno-octuloso
nic acid (KDO). LPS was degraded by mild acid hydrolysis to yield a degrade
d polysaccharide fraction and an insoluble lipid-A fraction. The main fatty
acids of the lipid-A fraction of the LPS were C12:O, C14:O, and 3-OH C14:O
for O158 strain whereas E, coli O142 lipid-A consisted of C12:O, C14:O, 3-
OH C14:O, and C16:O. The degraded polysaccharide fraction on gel permeation
chromatography gave a high, molecular weight O-chain fraction and a core o
ligosaccharide and a fraction containing degraded sugars. The chemical comp
osition of LPS and its fragmented products are reported in this communicati
on.