A kind of synthesis method of galnacα1,3gal or galα1,3gal glycosidic bond oligosaccharide

Abstract

The invention discloses a method for synthesizing GalNAcα1,3Gal or Galα1,3Gal glycosidic bond oligosaccharides. The method of the present invention comprises: performing α1,2-fucosylation modification on the non-reducing terminal Gal of the target oligosaccharide so that the substrate can be treated by α1,3-N-acetylgalactosamine glycosyltransferase or α1,3- Galactosyltransferase recognizes and synthesizes GalNAc(Fucα1,2)α1,3Gal or Gal(Fucα1,2)α1,3Gal glycosidic bonds, and then removes fucose to synthesize GalNAcα1,3Gal or Galα1,3Gal glycosidic bonds target oligosaccharides. The invention combines the high regioselectivity and high efficiency of enzymatic synthesis, and realizes the synthesis of target molecules with a relatively high yield. Moreover, the glycosyltransferase, sugar nucleoside generating enzyme and glycokinase used in the present invention are all derived from prokaryotic organisms, have the advantages of high protein expression, wide substrate adaptability, and high catalytic efficiency, and can be used for mass production.

Description

technical field [0001] The invention belongs to the technical field of glycosidic bond synthesis, and in particular relates to a method for synthesizing GalNAcα1,3Gal or Galα1,3Gal glycosidic bond oligosaccharides. Background technique [0002] The information disclosed in this background section is only intended to increase the understanding of the general background of the present invention, and is not necessarily taken as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. [0003] There are abundant sugar chains on the surface of cells, and sugar chains have important biological significance in cell recognition, cellular immunity, and virus infection. The abnormal expression of sugar chains on the cell surface is also very important to cancer cells. Studies have shown that oligosaccharides containing terminal GalNAcα1,3Gal glycosidic bonds are indicators of cervical cancer prognosis. The m...

AI Technical Summary

Problems solved by technology

However, there are also many limiting factors in the use of natural glycosyltransferases: the source of enzymes is limited; the instability and complexity of enzymes lead to difficulties in separation and purification; the glycosylation reaction catalyzed by enzymes requires expensive nucleoside activated sugars as glycosyls Donor; enzymes have strict substrate specificity and are less tolerant to unnatural or unusual substrates

The above shortcomings greatly limit the application of glycosidases and glycosyltransferases in the enzymatic modular synthesis of complex oligosaccharides

[0007] At present, no glycosidase or glycosyltransferase that directly catalyzes the synthesis of GalNAcα1,3Gal glycosidic bonds has been found, and the glycosyltransferases that synthesize Galα1,3Gal glycosidic bonds also have limited substrate adaptability

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