Substrate and donor specificity of glycosyl transferases

Abstract

It has been shown that all selectins recognize the carbohydrate epitopes sialyl Lewis x and sialyl Lewis a . For the establishment of the structure-activity relationship, the efficient synthesis of these tetrasaccharides and derivatives is therefore of vital interest. The glycosyl transferase-mediated approach is summarized with emphasis on the use of modified acceptors and modified sugar-nucleotide donors. A survey of the involved enzymes: b(1-3) and b(1-4)galactosyl transferases, a(2-3)sialyl transferase, FucT III and FucT VI reveals that the enzymatic synthesis is highly efficient for the rapid preparation of sialyl Lewis x -and sialyl Lewis a -derivatives.

Facile chemoenzymatic synthesis of Lewis a (Lea) antigen in gram-scale and sialyl Lewis a (sLea) antigens containing diverse sialic acid forms

“…Nevertheless, false negative and false positive results are possible and precautions are needed in interpreting the data [7,10,11]. sLe a oligosaccharides and analogs have been synthesized chemically [15][16][17][18][19][20] or chemoenzymatically [21][22][23][24]. Chemoenzymatic synthesis of sLe a antigens by sialidase (e.g.…”

“…Salmonella typhimurium LT2 sialidase)-catalyzed transglycosylation reaction using pnitrophenyl α-N-acetylneuraminide (Neu5AcαpNP) as the glycosyl donor and Le a trisaccharide as the acceptor was reported but with poor glycosylation yields [25]. All reported glycosyltransferase-catalyzed chemoenzymatic synthesis of sLe a antigens were carried out using recombinant mammalian enzymes or human milk enzymes including human α1-4-fucosyltransferase (FucT III) [26,27] or human milk [28,29] α1-3/4fucosyltransferase, rat liver [22,23,26] or porcine submaxillary [28] α2-3-sialyltransferase, and/or human β1-3galactosyltransferase [26]. In general, the reactions were carried out by sialyltransferase-catalyzed sialylation of β1-3-linked galactosides followed by fucosylation in the last step [23].…”

“…All reported glycosyltransferase-catalyzed chemoenzymatic synthesis of sLe a antigens were carried out using recombinant mammalian enzymes or human milk enzymes including human α1-4-fucosyltransferase (FucT III) [26,27] or human milk [28,29] α1-3/4fucosyltransferase, rat liver [22,23,26] or porcine submaxillary [28] α2-3-sialyltransferase, and/or human β1-3galactosyltransferase [26]. In general, the reactions were carried out by sialyltransferase-catalyzed sialylation of β1-3-linked galactosides followed by fucosylation in the last step [23]. sLe a derivatives with variations on the aglycon and the N-acyl group on the D-GlcNAc or the LFuc residue have been synthesized.…”

Characterization of bovine serum albumin glycated with glucose, galactose and lactose.

“…There is a large interest in obtaining glycoconjugates containing pure well-characterized oligosaccharides for use in biological studies, however, enzymatic synthesis is costly and complicated, since the number of glycosyltransferases available is limited (Ernst & Oehrlein, 1999). In contrast, there is evidence that under physiological conditions glucose reacts non-enzymatically with a wide variety of proteins to form glycated products.…”

Chemical and Biological Strategies for Engineering Cell Surface Glycosylation

“…This means that well-characterized synthetic oligosaccharides can be delivered to the cell surface in a controlled fashion (Srivastava et al 1992, De Vries et al 1997. Glycosyltransferases are frequently used in the construction of the oligosaccharide of interest because they require no protection and deprotection steps, reaction conditions are mild, and stereo-selectivity is unparalleled (Ernst & Oehrlein 1999).…”