title: Occurrence of glycine in the core oligosaccharides of Hafnia alvei lipopolysaccharides--identification of disubstituted glycoform.
abstract: Endotoxins (lipopolysaccharides, LPS) are the main surface antigens and virulence factors of Gram-negative bacteria involved for example in the development of nosocomial infections and sepsis. They consist of three main regions: O-specific polysaccharide, core oligosaccharide, and lipid A. Bacteria modify LPS structure to escape the immune defence, but also to adapt to environmental conditions. LPS's structures are highly diversified in the O-specific polysaccharide region to evade bactericidal factors of immune system, but retain some common epitopes that are potential candidates for therapeutic strategies against bacterial infections. Common occurrence of glycine within the structure of LPS is a known phenomenon and was previously reported for variety of species. Since glycine residue substitutes mainly core oligosaccharide of LPS, especially inner core region, it was also considered as a part of common epitope for broad-reactive antimicrobial antibodies. Herein, we used multiple-stage electrospray ionisation mass spectrometry to identify glycine substitution in core oligosaccharide type characteristic for Hafnia alvei LPS, and isolated from five strains of different O-serotypes: 32, PCM 1190, PCM 1192, PCM 1200, and PCM 1209. The location of glycine in core oligosaccharide was determined in detail for LPS 1190 using ESI-MS(n). Three glycoforms were identified, including two mono-glycinylated and one diglycinylated core oligosaccharides.
authors.affiliation: Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, PL-53-114 Wroclaw, Poland; Department of Biotechnology, Mass Spectrometry Laboratory, Wroclaw Research Center EIT+, Stablowicka 147, PL-54-066 Wroclaw, Poland.
authors.forename: Tomasz K
authors.initials: TK
authors.lastname: Gozdziewicz
authors.affiliation: Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, PL-53-114 Wroclaw, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Man-Kupisinska
authors.affiliation: Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, PL-53-114 Wroclaw, Poland; Department of Biotechnology and Molecular Biology, University of Opole, PL-45-035 Opole, Poland.
authors.forename: Czesław
authors.initials: C
authors.lastname: Lugowski
authors.affiliation: Department of Immunochemistry, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, R. Weigla 12, PL-53-114 Wroclaw, Poland. Electronic address: jolanta.lukasiewicz@iitd.pan.wroc.pl.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Lukasiewicz
mesh_terms: D002240:Carbohydrate Sequence; D005998:Glycine / Q000737:chemistry*; D020611:Hafnia alvei / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000032:analysis / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D008070:Lipopolysaccharides; D005998:Glycine
keywords: Core oligosaccharide; ESI; Endotoxin; Glycine; Lipopolysaccharide