Structural study on lipid A and the O-specific polysaccharide of the lipopolysaccharide from a clinical isolate of Bacteroides vulgatus from a patient with Crohn's disease.
Bacteroides vulgatus has been shown to be involved in the aggravation of colitis. Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B. vulgatus and characterized the structure of CPS. In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS. LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction. Lipid A was isolated by preparative TLC, and its structure determined by MS and NMR to be similar to that of Bacteroides fragilis except for the number of fatty acids. The polysaccharide fraction was subjected to gel-filtration chromatography to give an OPS-rich fraction. The structure of OPS was determined by chemical analysis and NMR spectroscopy to be a polysaccharide composed of the following repeating unit: [-->4)alpha-L-Rhap(1-->3)beta-D-Manp(1-->].
Hashimoto
Masahito
M
Research Institute, International Medical Center of Japan, Tokyo.
Kirikae
Fumiko
F
Dohi
Taeko
T
Adachi
Seizi
S
Kusumoto
Shoichi
S
Suda
Yasuo
Y
Fujita
Tsuyoshi
T
Naoki
Hideo
H
Kirikae
Teruo
T
D001439:Bacteroides / Q000737:chemistry* / Q000302:isolation & purification / Q000472:pathogenicity; D002236:Carbohydrate Conformation; D003424:Crohn Disease / Q000382:microbiology; D006801:Humans; D008050:Lipid A / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D019081:O Antigens / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014774:Virulence
D008050:Lipid A; D008070:Lipopolysaccharides; D019081:O Antigens