A newly discovered cholesteryl galactoside from Borrelia burgdorferi.
Two major glycolipids, which comprise approximately 36% of the total lipid mass from Borrelia burgdorferi, the etiological agent of Lyme disease, were investigated. We determined the fatty acid type, sugar identity, anomeric configuration, and substituent type and position. The structures were identified as cholesteryl 6-O-acyl-beta-d-galactopyranoside (B. burgdorferi glycolipid 1, BbGL-I), and 1,2-di-O-acyl-3-O-alpha-d-galactopyranosyl-sn-glycerol (BbGL-II). The major fatty acids were palmitate and oleate. The structures were corroborated by gas-liquid chromatography MS, matrix-assisted laser desorption/ionization time-of-flight spectroscopy, fast atom bombardment MS, detailed NMR spectrometry, and metabolic labeling. This is a previously undescribed demonstration of a cholesteryl galactoside in bacteria. Lipopolysaccharide was not detected in B. burgdorferi. The two glycolipids have several properties suggesting they may function as lipopolysaccharide: both are main components of the bacterial membrane, surface exposed, and have a three-domain structure. BbGL-I elicited specific antibodies in mice and rabbits, and BbGL-II elicited antibodies that reacted with both glycolipids.
Ben-Menachem
Gil
G
Laboratory of Developmental and Molecular Immunity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. gilben@nih.gov
Kubler-Kielb
Joanna
J
Coxon
Bruce
B
Yergey
Alfred
A
Schneerson
Rachel
R
D000818:Animals; D025065:Borrelia burgdorferi / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002784:Cholesterol / Q000737:chemistry*; D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D002855:Chromatography, Thin Layer; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005690:Galactose / Q000737:chemistry; D005697:Galactosides / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry; D006017:Glycolipids / Q000737:chemistry* / Q000378:metabolism; D050356:Lipid Metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D051379:Mice; D008956:Models, Chemical; D008969:Molecular Sequence Data; D019301:Oleic Acid / Q000737:chemistry; D010168:Palmitates / Q000737:chemistry; D017434:Protein Structure, Tertiary; D012503:Saponins / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
C475930:1-O-palmitoyl-2-O-oleyl-3-O-galactopyranosyl-sn-glycerol; D005697:Galactosides; D006017:Glycolipids; D008070:Lipopolysaccharides; D010168:Palmitates; D012503:Saponins; C475929:cholesteryl 6-O-palmitoylgalactopyranoside; D019301:Oleic Acid; D002784:Cholesterol; D005990:Glycerol; D005690:Galactose