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

Research paper by Nova N Tasnima, Hai H Yu, Xuebin X Yan, Wanqing W Li, An A Xiao, Xi X Chen

Indexed on: 19 Dec '18Published on: 19 Dec '18Published in: Carbohydrate Research



Abstract

An efficient streamlined chemoenzymatic approach has been developed for gram-scale synthesis of Lewis a angtigen (LeβProN) and a library of sialyl Lewis a antigens (sLeβProN) containing different sialic acid forms. Intially, commercially available inexpensive N-acetylglucosamine (GlcNAc) was converted to its N'-glycosyl p-toluenesulfonohydrazide in one step. Followed by chemical glycosylation, GlcNAcβProN was synthesized using this protecting group-free method in high yield (82%). Sequential one-pot multienzyme (OPME) β1-3-galactosylation of GlcNAcβProN followed by OPME α1-4-fucosylation reactions produced target LeβProN in gram-scale. Structurally diverse sialic acid forms was successfully introduced using a OPME sialylation reation containing a CMP-sialic acid synthetase and Pasteurella multocida α2-3-sialyltransferase 1 (PmST1) mutant PmST1 M144D with or without a sialic acid aldolase to form sLeβProN containing naturally occurring or non-natural sialic acid forms in preparative scales. Copyright © 2018 Elsevier Ltd. All rights reserved.