Tài liệu Báo cáo Y học: The structures of the lipooligosaccharide and capsule polysaccharide of

The structures of the lipooligosaccharide and capsule polysaccharide

of Campylobacter jejuni genome sequenced strain NCTC 11168

Frank St. Michael, Christine M. Szymanski, Jianjun Li, Kenneth H. Chan, Nam Huan Khieu,

Suzon Larocque, Warren W. Wakarchuk, Jean-Robert Brisson and Mario A. Monteiro

Institute for Biological Sciences, National Research Council of Canada, Ottawa, Canada

Campylobacter jejuni infections are one of the leading causes

of human gastroenteritis and are suspected of being a pre￾cursor to Guillain–Barre´ and Miller–Fisher syndromes.

Recently, the complete genome sequence of C. jejuni NCTC

11168 was described. In this study, the molecular structure of

the lipooligosaccharide and capsular polysaccharide of

C. jejuni NCTC 11168 was investigated. The lipooligosac￾charide was shown to exhibit carbohydrate structures anal￾ogous to the GM1a and GM2 carbohydrate epitopes of

human gangliosides (shown below):

The high Mr capsule polysaccharide was composed of

b-D-Ribp, b-D-GalfNAc, a-D-GlcpA6(NGro), a uronic

acid amidated with 2-amino-2-deoxyglycerol at C-6, and

6-O-methyl-D-glycero-a-L-gluco-heptopyranose as a side￾branch (shown below):

The structural information presented here will aid in the

identification and characterization of specific enzymes that

are involved in the biosynthesis of these structures and may

lead to the discovery of potential therapeutic targets. In

addition, the correlation of carbohydrate structure with gene

complement will aid in the elucidation of the role of these

surface carbohydrates in C. jejuni pathogenesis.

Keywords: lipooligosaccharide; capsule; electron spray

ionization mass spectrometry; high-resolution magic angle

spinning NMR; heptose.

In humans, Campylobacter jejuni infection often gives rise to

enteritis and, in some regions, this Gram-negative bacterium

surpasses Salmonella, Shigella and Escherichia as the

primary cause of gastrointestinal disease [1,2]. Moreover,

C. jejuni infections have been linked to the more severe

clinical outcomes caused by Guillain–Barre´ [3,4] and

Miller–Fisher syndromes [5]. The subsequent paralysis

observed in Guillain-Barre´ and Miller–Fisher syndromes

is thought to be an autoimmune reaction due to molecular

mimicry of gangliosides by C. jejuni lipooligosaccharides

(LOS) [6,7].

In the pioneering studies carried out by Aspinall and

coworkers on the cell-surface carbohydrates from

Campylobacter species, it was observed that insoluble gels

from phenol-water extractions of bacterial cells yielded

mainly low Mr LOS, with core oligosaccharide linked to

lipid A, and the aqueous phases from such extractions

furnished high Mr glycans with extended polymers with

no attachment to lipid A as seen in the teichoic acid-like

P/PEtn

GM1a GM2 fl

6

b-Gal-(1fi3)- b-D-GalNAc-(1fi4)-b-D-Gal-(1fi3)-b-D-Gal-(1fi3)-L-a-D-Hep-(1fi3)-L-a-D-Hep-(1fi5)Kdo

32 2 4

›› › ›

21 1 1

a-Neu5Ac a-D-Gal b-D-Glc b-D-Glc

6-O-Me-D-a-L-glcHepp

1

fl

3

fi2)-b-D-Ribf-(1-5)-b-D-Galf NAc-(1-4)-a-D-GlcpA6(NGro)-(1fi

0

BBBB@

0

BBBB@

1

CCCCA

Correspondence to J.-R. Brisson, Institute for Biological Sciences,

National Research Council of Canada, Ottawa, Canada, K1A 0R6.

Fax: + 1 613 952 9092, Tel.: + 1 613 990 3244,

E-mail: [email protected]; M. Monteiro, Wyeth Vaccines

Research, 211 Bailey Road, West Henrietta, NY, 14586, USA.

Fax: + 1 585 273 751, Tel.: + 1 585 273 7667,

E-mail: [email protected]

Abbreviations: CE, capillary electrophoresis; ESI-MS, electron spray

ionization mass spectrometry; FAB, fast-atom bombardment;

HMBC, heteronuclear multiple bond coherence; HMQC, heteronu￾clear multiple quantum coherence; HR-MAS, high-resolution magic

angle spinning; HSQC, heteronuclear single quantum coherence;

KmR, kanamycin resistance; LOS, lipooligosaccharide; LPS, lipo￾polysaccharide; OS, oligosaccharide.

Dedication: The authors would like to dedicate this manuscript to

Professor Gerald Aspinall.

(Received 3 July 2002, revised 16 August 2002,

accepted 21 August 2002)

Eur. J. Biochem. 269, 5119–5136 (2002)  FEBS 2002 doi:10.1046/j.1432-1033.2002.03201.x