The first bacterial alpha 2-6-sialyltransferase cloned from Photobacterium damselae (Pd2,6ST) has been widely applied for the synthesis of various alpha 2-6-linked sialosides. However, the extreme substrate flexibility of Pd2,6ST makes it unsuitable for site-specific alpha 2-6-sialylation of complex substrates containing multiple galactose and/or N-acetylgalactosamine units. To tackle this problem, a general redox-controlled site-specific sialylation strategy using Pd2,6ST is described. This approach features site-specific enzymatic oxidation of galactose units to mask the unwanted sialylation sites and precisely controlling the site-specific alpha 2-6-sialylation at intact galactose or N-acetylgalactosamine units.
A facile one-pot two-enzyme chemoenzymatic approach has been established for the gram (Neu4,5Ac2α3Lac, 1.33 g) and preparative scale (Neu4,5Ac2α3LNnT) synthesis of monotreme milk oligosaccharides. Other O-acetyl-5-N-acetylneuraminic acid (Neu4,5Ac2)- or 4-O-acetyl-5-N-glycolylneuraminic acid (Neu4Ac5Gc) -containing α2-3-sialosides have also been synthesized in the preparative scale. Used as an effective
Chemoenzymatic Synthesis of Sialosides Containing 7-<i>N</i>- or 7,9-Di-<i>N</i>-acetyl Sialic Acid as Stable <i>O</i>-Acetyl Analogues for Probing Sialic Acid-Binding Proteins
(OPME) sialylation systems for highly efficient synthesis of sialosides containing multiple azido groups. Conversion of the azido groups to N-acetyl groups generated the desired sialosides. The hydrophobic and UV-detectable benzyloxycarbonyl (Cbz) group introduced in the synthetic acceptors of sialyltransferases was used as a removable protecting group for the propylamine aglycon of the target sialosides
The one-pot multienzyme (OPME) synthesis of human blood group H antigens and a human milk oligosaccharide (HMOS) with highly active Thermosynechococcus elongatus α1–2-fucosyltransferase
作者:Chao Zhao、Yijing Wu、Hai Yu、Ishita M. Shah、Yanhong Li、Jie Zeng、Bin Liu、David A. Mills、Xi Chen
DOI:10.1039/c5cc10646j
日期:——
LNFP I and human blood H group antigens were synthesized efficientlyviaone-pot multienzyme (OPME) fucosylation with a bacterial α1–2-fucosyltransferase.
<i>L. pneumophila</i>CMP-5,7-di-<i>N</i>-acetyllegionaminic acid synthetase (LpCLS)-involved chemoenzymatic synthesis of sialosides and analogues
作者:John B. McArthur、Abhishek Santra、Wanqing Li、Anoopjit S. Kooner、Ziqi Liu、Hai Yu、Xi Chen
DOI:10.1039/c9ob02476j
日期:——
5,7-Di-N-acetyllegionaminic acid (Leg5,7Ac2) is a bacterial nonulosonic acid (NulO) analogue of sialic acids, an important class of monosaccharides in mammals and in some bacteria. To develop efficient one-pot multienzyme (OPME) glycosylation systems for synthesizing Leg5,7Ac2-glycosides, Legionella pneumophila cytidine 5'-monophosphate (CMP)-Leg5,7Ac2 synthetase (LpCLS) was cloned and characterized
Sequential two-step multienzyme synthesis of tumor-associated sialyl T-antigens and derivatives
作者:Kam Lau、Hai Yu、Vireak Thon、Zahra Khedri、Meghan E. Leon、Bao K. Tran、Xi Chen
DOI:10.1039/c0ob01269f
日期:——
A series of α2–3-sialylated β1–3-linked galactosides, including sialyl T-antigens, 3′-sialyl galacto-N-biose, 3′-sialyl lacto-N-biose, and their derivatives containing natural and non-natural sialic acid forms have been synthesized from simple monosaccharides using an efficient sequential two-step multienzyme approach.