Synthesis method of GalNAc<alpha>1, 3Gal or Gal<alpha>1, 3Gal glycosidic bond oligosaccharide

Abstract

The invention discloses a synthesis method of GalNAc<alpha>1, 3Gal or Gal<alpha>1, 3Gal glycosidic bond oligosaccharide. The method comprises the following steps: a non-reductive tail end Gal of target oligosaccharide is subjected to <alpha>1, 2-fucosylation modification, so that a substrate can be recognized by <alpha>1, 3-N-acetylaminogalatose glycosyltransferase or <alpha>1, 3-galactose glycosyltransferase to synthesize GalNAc (Fuc<alpha>1, 2)<alpha>1, 3GAL or Gal (Fuc<alpha>1, 2)<alpha>1, 3Gal glycosidic, fucose is removed to synthesize target oligosaccharide containing a GalNAc<alpha>1, 3Gal or Gal<alpha>1, 3Gal glycosidic bond. The method combines high region selectivity and high efficiency of enzymatic synthesis together and realizes synthesis of a target molecule with a higher yield. The glycosyltransferase, glycoribosidase and glucokinse used in the method are all derived from prokaryotes, and the method has the advantages of high protein expression quantity, wide substrate adaptability, high catalysis efficiency and the like and can be applied to mass preparation.

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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