Chemoenzymatic Syntheses of Sialyloligosaccharides with Immobilized Sialidase

Abstract

The α‐glycosidic transfer of N‐acetylneuraminic acid (Neu5Ac) to the terminally bound galactose of the acceptor molecule is achieved with immobilized sialidase obtained from Vibrio cholerae. This is the first application of this enzyme in the catalysis of transglycosylation, which produces (2–6)‐ and (2–3)‐linked sialyloligosaccharides. These molecules often cannot be prepared by feasible synthetic methods, yet their physiological importance in glycoproteins and ‐lipids continue to generate interest.

Complete synthesis of 3′‐sialyl‐N‐acetyllactosamine by regioselective transglycosylation

“…The enzymatic synthesis of sialyl oligosaccharides in general, and of 3'-SLN in particular, has already been reported, but in all cases described so far at least a galactosyltransferase [21,22], a sialyltransferase [23] or both [10,24] have been used. When either transgalactosylation [11] or transsialylation was used [11,25,26] possible to obtain a high regioselectivity together kvith a high yield of synthesis; the subsequent use of T. cruzi trans-sialidase overcomes the regioselectivity problems of the transsialylation.…”

“…The multi-step chemical synthesis of this ~iologically important trisaccharide has been described [8], 9ut it is very laborious. In order to avoid multi-step chemical ~ynthesis, enzymatic methods have been developed using gly--osyltransferases as catalysts [9][10][11]. Moreover, the latter enzymes require activated sugars which, in spite of recent imigrovements in production by biochemical recycling [12], still ire costly and industrially non-attractive substrates.…”

All‐Transglycolytic Synthesis and Characterization of sialyl(α2–3)galactosyl(β1–4)xylosyl‐p‐nitrophenyl(β1–, an Oligosaccharide Derivative Related to Glycosaminoglycan Biosynthesis

“…From a practical point of view, the use of synthetic substrates is more advantageous since the procedures of synthesis of these substrates have been described (Myers et al, 1980;Eschenfelder and Brossmer, 1987) and the aglycone part of these substrates cannot act as acceptor. Some results have been reported concerning the enzymatic synthesis of sialyloligosaccharides using sialyltransferase and/or trans-sialylation (Nilsson, 1989 ;Thiem and Treder, 1986 ;Thiem and Sauerbrei, 1991;Maru et al, 1992;Ajisaka et al, 1994;Tanaka et al, 1995). The former enzymes give good regioselectivity but require activated substrates, the latter enzymes give low regioselectivity.…”

Strategies for the Chemical Synthesis of Glycoconjugates

“…Glycosidases have also been extensively investigated for their use in glycoside bond formation (Thiem and Sauerbrei, 1991;Nilsson, 1996). However, the reversibility, lower regio-and dia- …”