Oxford, UK: Blackwell Science Ltd. on behalf of the Federation of European Biochemical Societies
Center for Medicine and Biosciences, Borstel Research Center, Germany, Department of Biomolecular Mass Spectrometry, Bijvoet Center for Biomolecular Research, Utrecht University, the Netherlands, Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
The lipopolysaccharides (LPS) from Escherichia coli rough mutant strains F470 (R1 core type) and F576 (R2 core type) were deacylated yielding in each case a mixture of oligosaccharides with one predominant product which was isolated using high-performance anion-exchange chromatography. In addition, one oligosaccharide present in minor quantities was isolated from LPS of E. coli strain F576 (R2 core type). The structures of the oligosaccharides were determined by chemical analyses and NMR spectroscopic experiments. Furthermore, de-O-acylated and dephosphorylated LPS preparations were investigated by fast-atom bombardment and collision induced dissociation tandem mass spectrometry. The combined data allow us to deduce the following carbohydrate backbones of the E. coli R1 and R2 core types which share the following structure (Scheme 1 [see formula in text], but differ in the substituents R1 and R2 which for the R1 core type are predominantly: R1 = a-Gal-(1→2)-a-Gal-(1→2)-[b-Glc-(1→3)]a-Glc-(1→3)-a-Glc-, R2 = H and to a minor extent: R1 = a-Gal-(1→2)-a-Gal-(1→2)-[b-Glc-(1→3)]-a-Glc-(1→3)-a-Glc-, R2 = a-GlcN and for the R2 core type predominantly: R1 = a-GlcNAc-(1→2)-a-Glc-(1→2)-a-Glc-(1→3)-[a-Gal-(1→6)]-a-Glc-, R2 = H and to a minor extent: R1 = a-GlcNAc-[b-Gal-(1→4)]-(1→2)-a-Glc-(1→2)-a-Glc-[a-Gal-(1→6)]-(1→3)-a-Glc-, R2 = H in which all sugars are d-pyranoses (L,D-Hep, L-glycero-D-manno-heptopyranose; P, phosphate).
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6 C7 C8
0,6,6,4 aXKdop ? ? 35.9 66.3 67.4 72.5 71.5 63.5
0,6,6,5,3,3,3,2,2 aDGlcpN 96.8 55.4 ? 70.3 73.1 61.2
0,6,6,5,3,3,3,2,4 bDGalp 103.5 71.6 73.2 69.3 76.0 ?
0,6,6,5,3,3,3,2 aDGlcp 93.4 75.7 69.6 78.5 71.8 60.3
0,6,6,5,3,3,3 aDGlcp 95.2 74.9 72.0 71.1 72.2 61.7
0,6,6,5,3,3,6 aDGalp 98.8 69.2 69.5 69.8 ? 61.7
0,6,6,5,3,3 aDGlcp 101.4 70.7 77.8 71.5 71.7 66.5
0,6,6,5,3,4 P
0,6,6,5,3,7 aXLDmanHepp 101.1 71.7 71.3 67.1 72.6 ? ?
0,6,6,5,3 aXLDmanHepp 102.6 70.6 79.3 68.8 73.6 68.3 69.6
0,6,6,5,4 P
0,6,6,5 aXLDmanHepp 99.0 71.5 76.3 69.9 73.8 69.5 ?
0,6,6 aXKdop ? ? 34.8 71.8 68.4 72.9 70.3 64.4
0,6,4 P
0,6 bDGlcpN 101.6 56.6 73.8 74.7 ? 63.6
0 aDGlcpN 93.1 55.7 72.1 70.5 72.7 70.5
P
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6 H7 H8
0,6,6,4 aXKdop - - 1.76-2.15 4.16 4.06 3.66 4.01 3.72-3.74
0,6,6,5,3,3,3,2,2 aDGlcpN 5.13 2.92 3.69 3.44 3.96 3.76-3.83
0,6,6,5,3,3,3,2,4 bDGalp 4.44 3.54 3.64 3.89 ? ?
0,6,6,5,3,3,3,2 aDGlcp 5.45 3.76 4.00 3.76 3.93 3.84-3.90
0,6,6,5,3,3,3 aDGlcp 5.71 3.66 3.91 3.34 4.16 3.77-3.95
0,6,6,5,3,3,6 aDGalp 4.97 3.78 3.98 4.02 ? 3.73-3.73
0,6,6,5,3,3 aDGlcp 5.31 3.59 4.12 3.53 4.09 3.88-3.91
0,6,6,5,3,4 P
0,6,6,5,3,7 aXLDmanHepp 4.87 3.93 3.86 3.81 3.66 ? 3.72-?
0,6,6,5,3 aXLDmanHepp 5.22 4.39 4.07 4.32 3.72 4.28 3.65-3.70
0,6,6,5,4 P
0,6,6,5 aXLDmanHepp 5.21 4.00 4.04 4.35 4.34 4.16 3.89-3.98
0,6,6 aXKdop - - 1.89-2.19 4.10 4.22 3.69 3.84 3.64-3.91
0,6,4 P
0,6 bDGlcpN 4.65 2.87 3.66 3.70 3.73 3.24-3.65
0 aDGlcpN 5.50 3.05 3.74 3.53 4.11 3.74-4.30
P
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6 C7/H7 C8/H8
0,6,6,4 aXKdop 35.9/1.76-2.15 66.3/4.16 67.4/4.06 72.5/3.66 71.5/4.01 63.5/3.72-3.74
0,6,6,5,3,3,3,2,2 aDGlcpN 96.8/5.13 55.4/2.92 ?/3.69 70.3/3.44 73.1/3.96 61.2/3.76-3.83
0,6,6,5,3,3,3,2,4 bDGalp 103.5/4.44 71.6/3.54 73.2/3.64 69.3/3.89 76.0/? ?/?
0,6,6,5,3,3,3,2 aDGlcp 93.4/5.45 75.7/3.76 69.6/4.00 78.5/3.76 71.8/3.93 60.3/3.84-3.90
0,6,6,5,3,3,3 aDGlcp 95.2/5.71 74.9/3.66 72.0/3.91 71.1/3.34 72.2/4.16 61.7/3.77-3.95
0,6,6,5,3,3,6 aDGalp 98.8/4.97 69.2/3.78 69.5/3.98 69.8/4.02 ?/? 61.7/3.73-3.73
0,6,6,5,3,3 aDGlcp 101.4/5.31 70.7/3.59 77.8/4.12 71.5/3.53 71.7/4.09 66.5/3.88-3.91
0,6,6,5,3,4 P
0,6,6,5,3,7 aXLDmanHepp 101.1/4.87 71.7/3.93 71.3/3.86 67.1/3.81 72.6/3.66 ?/? ?/3.72-?
0,6,6,5,3 aXLDmanHepp 102.6/5.22 70.6/4.39 79.3/4.07 68.8/4.32 73.6/3.72 68.3/4.28 69.6/3.65-3.70
0,6,6,5,4 P
0,6,6,5 aXLDmanHepp 99.0/5.21 71.5/4.00 76.3/4.04 69.9/4.35 73.8/4.34 69.5/4.16 ?/3.89-3.98
0,6,6 aXKdop 34.8/1.89-2.19 71.8/4.10 68.4/4.22 72.9/3.69 70.3/3.84 64.4/3.64-3.91
0,6,4 P
0,6 bDGlcpN 101.6/4.65 56.6/2.87 73.8/3.66 74.7/3.70 ?/3.73 63.6/3.24-3.65
0 aDGlcpN 93.1/5.50 55.7/3.05 72.1/3.74 70.5/3.53 72.7/4.11 70.5/3.74-4.30
P
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Found 1 record.
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