Donor substrate promiscuity of bacterial β1–3-N-acetylglucosaminyltransferases and acceptor substrate flexibility of β1–4-galactosyltransferases

Abstract

β1–3-N-Acetylglucosaminyltransferases (β3GlcNAcTs) and β1–4-galactosyltransferases (β4GalTs) have been broadly used in enzymatic synthesis of N-acetyllactosamine (LacNAc)-containing oligosaccharides and glycoconjugates including poly-LacNAc, and lacto-N-neotetraose (LNnT) found in the milk of human and other mammals. In order to explore oligosaccharides and derivatives that can be synthesized by the combination of β3GlcNAcTs and β4GalTs, donor substrate specificity studies of two bacterial β3GlcNAcTs from Helicobacter pylori (Hpβ3GlcNAcT) and Neisseria meningitidis (NmLgtA), respectively, using a library of 39 sugar nucleotides were carried out. The two β3GlcNAcTs have complementary donor substrate promiscuity and 13 different trisaccharides were produced. They were used to investigate the acceptor substrate specificities of three β4GalTs from Neisseria meningitidis (NmLgtB), Helicobacter pylori (Hpβ4GalT), and bovine (Bβ4GalT), respectively. Ten of the 13 trisaccharides were shown to be tolerable acceptors for at least one of these β4GalTs. The application of NmLgtA in one-pot multienzyme (OPME) synthesis of two trisaccharides including GalNAcβ1–3Galβ1–4GlcβProN3 and Galβ1–3Galβ1–4Glc was demonstrated. The study provides important information for using these glycosyltransferases as powerful catalysts in enzymatic and chemoenzymatic syntheses of oligosaccharides and derivatives which can be useful probes and reagents.

Highly efficient chemoenzymatic synthesis and facile purification of α-Gal pentasaccharyl ceramide Galα3nLc4βCer

“…Formation of trisaccharyl sphingosine Lc 3 βSph (GlcNAcβ3Galβ4GlcβSph, 4 ) from LacβSph ( 5 ) was achieved by a one-pot four-enzyme N-acetylglucosamine (GlcNAc) activation and transfer system containing Bifidobacterium longum (strain ATCC55813) N -acetylhexosamine-1-kinase (BLNahK), 46 Pasteurella multocida N -acetylglucosamine uridylyltransferase (PmGlmU), 47 Pasteurella multocida inorganic pyrophosphatase (PmPpA), 48 and Neisseria meningitidis β1–3- N -acetylglucosaminyltransferase (NmLgtA) 49 in Tris-HCl buffer (100 mM, pH 8.0) at 37 °C for 52 hours. The BLNahK, PmGlmU, and PmPpA allowed in situ formation of uridine 5′-diphosphate- N -acetylglucosamine (UDP-GlcNAc), the sugar nucleotide donor substrate, efficiently and directly from monosaccharide GlcNAc for NmLgtA-catalyze formation of Lc 3 βSph ( 4 ).…”

“…The obtained Lc 3 βSph ( 4 ) was used for synthesizing nLc 4 βSph ( 3 ) using an improved OPME galactose (Gal) activation and transfer system 50 containing Streptococcus pneumoniae TIGR4 galactokinase (SpGalK), 51 Bifidobacterium longum UDP-sugar pyrophosphorylase (BLUSP), 50 PmPpA, and Neisseria meningitidis β1–4-galactosyltransferase (NmLgtB) 48, 49 in Tris-HCl buffer (100 mM, pH 8.0) at 37 °C for 30 hours. The SpGalK, BLUSP, and PmPpA allowed in situ formation of uridine 5′-diphosphate-galactose (UDP-Gal), the donor substrate of NmLgtB, from monosaccharide galactose (Gal) for the formation of LNnTβSph ( 3 ).…”

Enzymatic and Chemoenzymatic Syntheses of Disialyl Glycans and Their Necrotizing Enterocolitis Preventing Effects

“…Instead of carrying out α2–6-sialylation to introduce two α2–6-linked Neu5Ac simultaneously after the formation of LNnT using a β1–4-galactosyltransferase-catalyzed one-pot multienzyme (OPME) reaction, the formation of α2–3- and α2–6-linked Neu5Ac in DS′LNnT ( 5 ) was accomplished by α2–6-sialylation of the trisaccharide core GlcNAcβ1–3Galβ1–4Glc (Lc 3 , 10 ) followed by sequential extension of the core with β1–4-galactosylation and α2–3-sialylation. 17 As shown in Scheme 3, trisaccharide GlcNAcβ1–3Galβ1–4Glc (Lc 3 , 10 ) obtained from lactose in a one-pot four-enzyme GlcNAc-activation and transfer reaction 12 containing recombinant enzymes Bifidobacterium longum strain ATCC55813 N -acetylhexosamine-1-kinase (BLNahK), 18 Pasteurella multocida N -acetylglucosamine uridylyltransferase (PmGlmU), 19 Pasteurella multocida inorganic pyrophosphatase (PmPpA), 20 and Neisseria meningitidis β1–3- N -acetylglucosaminyltransferase (NmLgtA) 21 was used for α2–6-sialylation by the OP2E system containing NmCSS and Pd2,6ST. Tetrasaccharide GlcNAcβ1–3(Neu5Acα2–6)Galβ1–4Glc ( 11 ) (0.3 g) was obtained in an excellent 96% yield.…”

“…Lac, Gal, and GalNAc were purchased from Fisher Scientific, Neu5Ac was from Atomole Scientific, UTP and CTP were from Chemfun Medical Technology Co., and ATP was from Beta Pharm Inc. Lacto- N -tetraose (LNT) was from Elicityl (Crolles, France). Recombinant enzymes Bifidobacterium longum strain ATCC55813 N -acetylhexosamine-1-kinase (BLNahK), 18 Pasteurella multocida N -acetylglucosamine uridyltransferase (PmGlmU), 19 Pasteurella multocida inorganic pyrophosphatase (PmPpA), 20 Neisseria meningitidis β1–3- N –acetylglucosaminyltransferase (NmLgtA), 21 Escherichia coli galactokinase (EcGalK), 22 Bifidobacterium longum UDP-sugar pyrophosphorylase (BLUSP), 23 Neisseria meningitidis β1–4-galactosyltransferase (NmLgtB), 20 Neisseria meningitidis CMP-sialic acid synthetase (NmCSS), 13 Photobacterium damselae α2–6-sialyltransferase (Pd2,6ST), 14 Pasteurella multocida α2–3-sialyltransferase 1 M144D mutant (PmST1 M144D), 24 Bifidobacterium infantis D-galactosyl-β1,3- N -acetyl-D-hexosamine phosphorylase (BiGalHexNAcP), 26 and Campylobacter jejuni β1–3-galactosyltransferase (CjCgtB) 33 were expressed and purified as described previously. HMOs used were obtained previously.…”

Protecting‐Group‐Controlled Enzymatic Glycosylation of Oligo‐N‐Acetyllactosamine Derivatives

“…These substrates were exposed to the microbial fucosyl transferase Hp39-FT in the presence of GDP-fucose, and the conversion to the corresponding Lewis X( Le x )containing oligosaccharides 23-27 was monitored by capillary electrophoresis-mass spectrometry (CE-MS). [8] It was found that LacNAc 17 and LacNHTFA 18 were readily converted into the Le x -containing products 23 and 24.O nt he other hand, the presence of the Cbz-and Bsmoc-protecting groups of 19 and 20, respectively,c onsiderably slowed down the fucosylation and only partial product formation was observed. Strikingly,n oc onversion to Le x was observed for LacNH-Boc 21 and LacNH 2 22.S imilar results were obtained when FUT5 was employed.…”