Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
The structure was elucidated in this paperNCBI PubMed ID: 23000215Publication DOI: 10.1016/j.carres.2012.05.015Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: S. Drouillard sophie.drouillard

cermav.cnrs.fr
Institutions: Centre de recherche sur Macromolecules Vegetales (CERMAV-CNRS), BP 53, F-38041 Grenoble Cedex 9, France
The α-Gal epitope is a carbohydrate structure, Galα-3Galβ-4GlcNAc-R, expressed on glycoconjuguates in many mammals, but not in humans. Species that do not express this epitope have present in their serum large amounts of natural anti-Gal antibodies, which contribute to organ hyperacute rejection during xenotransplantation. We first describe the efficient conversion of lactose into isoglobotriaose (Galα-3Galβ-4Glc) using high cell density cultures of a genetically engineered Escherichia coli strain expressing the bovine gene for α-1,3-galactosyltransferase. Attempts to produce the Galili pentasaccharide (Galα-3Galβ-4GlcNAcβ-3Galβ-4Glc) by additionally expressing the Neisseria meningitis lgtA gene for β-1,3-N-acetylglucosaminyltransferase and the Helicobacter pylori gene for β-1,4-galactosyltransferase were unsuccessful and led to the formation of a series of long chain oligosaccharides formed by the repeated addition of the trisaccharide motif [Galβ-4GlcNAcβ-3Galα-3] onto a lacto-N-neotetraose primer. The replacement of LgtA by a more specific β-1,3-N-acetylglucosaminyltransferase from H. pylori, which was unable to glycosylate α-galactosides, prevented the formation of these unwanted compounds and allowed the successful formation of the Galili pentasaccharide and longer α-Gal epitopes.
Escherichia coli, Oligosaccharides, fermentation, Metabolic engineering, α-Gal epitope, a-Gal epitope
Structure type: oligomer
Location inside paper: p.88, fig.4, (4)
Contained glycoepitopes: IEDB_115013,IEDB_130645,IEDB_130646,IEDB_130649,IEDB_130697,IEDB_135813,IEDB_135815,IEDB_136044,IEDB_136906,IEDB_137340,IEDB_137472,IEDB_137776,IEDB_1391966,IEDB_140108,IEDB_140109,IEDB_140110,IEDB_140122,IEDB_141496,IEDB_141794,IEDB_141807,IEDB_142351,IEDB_142487,IEDB_142488,IEDB_146664,IEDB_146694,IEDB_149144,IEDB_149558,IEDB_151528,IEDB_151531,IEDB_153197,IEDB_190606,IEDB_418918,IEDB_689191,IEDB_918314,IEDB_983931,SB_145,SB_165,SB_166,SB_173,SB_187,SB_192,SB_195,SB_30,SB_40,SB_6,SB_7,SB_87,SB_88
Methods: 13C NMR, 1H NMR, TLC, ESI-MS, chemical methods, genetic methods
Enzymes that release or process the structure: a-1,3-galactosyltransferase (recombinant α-3GalT), lgtA, β-1,4-galactosyltransferase (recombinant β-4GalT)
Synthetic data: enzymatic
Comments, role: genetically engineered strain Escherichia coli
Related record ID(s): 29178, 29490, 29491, 29492, 29493, 29494, 29496, 29497, 29498, 29499, 29500, 29501, 29502, 29503, 29504, 29505, 29506, 29507, 29508, 29509, 29510, 29511, 29512, 29513, 29514
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GTC:G29941TA
Show glycosyltransferases
NMR conditions: in D2O at 293 K
[as TSV]
13C NMR data:
Linkage Residue C1 C2 C3 C4 C5 C6
4,3,4,3,3,4 bDGalp 104.09 ? ? ? ? 62.28
4,3,4,3,3,2 Ac 176.18 23.41
4,3,4,3,3 bDGlcpN 103.96 56.50 ? 79.36 ? 61.13
4,3,4,3 aDGalp 96.90 ? 80.30 70.18 71.67 62.03
4,3,4 bDGalp 103.87 ? 78.41 66.09 ? 62.24
4,3,2 Ac 176.18 23.41
4,3 bDGlcpN 104.04 56.43 ? 79.47 ? 61.13
4 bDGalp 104.09 ? 83.28 69.59 ? 62.24
bDGlcp 96.98 75.01 ? 79.47 ? 61.28
1H NMR data:
Linkage Residue H1 H2 H3 H4 H5 H6
4,3,4,3,3,4 bDGalp 4.51 3.58 ? ? ? ?
4,3,4,3,3,2 Ac - 2.06
4,3,4,3,3 bDGlcpN 4.76 3.84 ? ? ? ?
4,3,4,3 aDGalp 5.14 3.94 4.06 4.27 4.25 ?
4,3,4 bDGalp 4.58 3.69 3.82 4.22 ? ?
4,3,2 Ac - 2.06
4,3 bDGlcpN 4.73 3.84 ? 3.79 ? ?
4 bDGalp 4.47 3.62 3.76 4.18 ? ?
bDGlcp 4.69 3.31 ? 3.68 ? ?
1H/13C HSQC data:
Linkage Residue C1/H1 C2/H2 C3/H3 C4/H4 C5/H5 C6/H6
4,3,4,3,3,4 bDGalp 104.09/4.51 ?/3.58 ?/? ?/? ?/? 62.28/?
4,3,4,3,3,2 Ac 23.41/2.06
4,3,4,3,3 bDGlcpN 103.96/4.76 56.50/3.84 ?/? 79.36/? ?/? 61.13/?
4,3,4,3 aDGalp 96.90/5.14 ?/3.94 80.30/4.06 70.18/4.27 71.67/4.25 62.03/?
4,3,4 bDGalp 103.87/4.58 ?/3.69 78.41/3.82 66.09/4.22 ?/? 62.24/?
4,3,2 Ac 23.41/2.06
4,3 bDGlcpN 104.04/4.73 56.43/3.84 ?/? 79.47/3.79 ?/? 61.13/?
4 bDGalp 104.09/4.47 ?/3.62 83.28/3.76 69.59/4.18 ?/? 62.24/?
bDGlcp 96.98/4.69 75.01/3.31 ?/? 79.47/3.68 ?/? 61.28/?
1H NMR data:
| Linkage | Residue | H1 | H2 | H3 | H4 | H5 | H6 |
| 4,3,4,3,3,4 | bDGalp | 4.51 | 3.58 | ? | ? | ? | ? |
| 4,3,4,3,3,2 | Ac |
| 2.06 | |
| 4,3,4,3,3 | bDGlcpN | 4.76 | 3.84 | ? | ? | ? | ? |
| 4,3,4,3 | aDGalp | 5.14 | 3.94 | 4.06 | 4.27 | 4.25 | ? |
| 4,3,4 | bDGalp | 4.58 | 3.69 | 3.82 | 4.22 | ? | ? |
| 4,3,2 | Ac |
| 2.06 | |
| 4,3 | bDGlcpN | 4.73 | 3.84 | ? | 3.79 | ? | ? |
| 4 | bDGalp | 4.47 | 3.62 | 3.76 | 4.18 | ? | ? |
| | bDGlcp | 4.69 | 3.31 | ? | 3.68 | ? | ? |
|
13C NMR data:
| Linkage | Residue | C1 | C2 | C3 | C4 | C5 | C6 |
| 4,3,4,3,3,4 | bDGalp | 104.09 | ? | ? | ? | ? | 62.28 |
| 4,3,4,3,3,2 | Ac | 176.18 | 23.41 | |
| 4,3,4,3,3 | bDGlcpN | 103.96 | 56.50 | ? | 79.36 | ? | 61.13 |
| 4,3,4,3 | aDGalp | 96.90 | ? | 80.30 | 70.18 | 71.67 | 62.03 |
| 4,3,4 | bDGalp | 103.87 | ? | 78.41 | 66.09 | ? | 62.24 |
| 4,3,2 | Ac | 176.18 | 23.41 | |
| 4,3 | bDGlcpN | 104.04 | 56.43 | ? | 79.47 | ? | 61.13 |
| 4 | bDGalp | 104.09 | ? | 83.28 | 69.59 | ? | 62.24 |
| | bDGlcp | 96.98 | 75.01 | ? | 79.47 | ? | 61.28 |
|
 The spectrum also has 15 signals at unknown positions (not plotted). |
There is only one chemically distinct structure: