trans-sialidase catalyzed sialylation of β-galactosyldisaccharide with an introduction of β-galactosidase
trans-sialidase catalyzed sialylation of β-galactosyldisaccharide with an introduction of β-galactosidase
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DOI：
10.1016/s0141-0229(00)00313-6
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发表时间：
2001-02-01
影响因子：
3.4
通讯作者：
Kim, BG
中科院分区：
文献类型：
--
作者：
Lee, SG;Kim, BG
将β-半乳糖苷酶引入转唾液酸酶反应中，即唾液酸从供体底物（α 2，3-唾液酸乳糖）转移到受体底物（β-半乳糖基二糖）的反应中，可以通过水解乳糖（供体的副产物）来提高所需唾液酸化三糖的产率。当用化学计量量（2 mM）的α 2，3-唾液酸乳糖和Gal β（1，3）GlcNAc进行转唾液酸酶反应时，通过大肠杆菌β-半乳糖苷酶的偶联，NeuAc α（2，3）Gal β（1，3）GlcNAc的产率从45%增加到75%。此外，通过改变偶联反应中的底物比例，即α 2，3-唾液酸乳糖比Gal β（1，3）GlcNAc过量两倍，基于Gal β（1，3）GlcNAc的量，实现了95%以上的产率。然而，在该反应中，Gal β（1，3）GlcNAc比α 2，3-唾液酸乳糖过量两倍对于NeuAc α（2，3）Gal β（1，3）GlcNAc的纯化更理想，因为实现了α 2，3-唾液酸乳糖的完全消耗。偶联反应的效率受到β-半乳糖苷酶对受体底物的特异性的影响。当以Gal β（1.6）GlcNAc为受体时，E.大肠杆菌β-半乳糖苷酶在偶联反应中水解Gal β（1，6）GlcNAc以及乳糖，导致所需唾液酸化三糖的产率显著降低。通过使用环状芽孢杆菌β-半乳糖苷酶可以提高Gal β（1，6）GlcNAc的唾液酸化的转化率。(C)2001 Elsevier Science Inc. All rights reserved.
Introduction of beta -galactosidase into a trans-sialidase reaction, i.e. sialic acid transfer reaction from a donor substrate (alpha2,3-sialyllactose) to an acceptor substrate (beta -galactosyldisaccharide), could improve the yield of desired sialylated trisaccharide by hydrolyzing lactose, a byproduct from the donor. When trans-sialidase reaction was performed with stoichiometric amounts (2 mM) of alpha2,3-sialyllactose and Gal beta (1,3)GlcNAc, the yield of NeuAc alpha (2,3)Gal beta (1,3)GlcNAc increased from 45% to 75% by the coupling of Escherichia coli beta -galactosidase. Furthermore, by changing the substrate ratio in the coupled reaction, i.e. two-fold excess of alpha2,3-sialyllactose to Gal beta (1,3)GlcNAc, above 95% of yield was achieved based on the amount of Gal beta (1,3)GlcNAc. However, two-fold excess of Gal beta (1,3)GlcNAc to alpha2,3-sialyllactose in this reaction was more desirable for the purification of NeuAc alpha (2,3)Gal beta (1,3)GlcNAc, since complete consumption of alpha2,3-sialyllactose was achieved. Efficiency of the coupled reaction was affected by the specificity of P-galactosidase for acceptor substrate. When Gal beta (1.6)GlcNAc was used as the acceptor, E. coli beta -galactosidase hydrolyzed Gal beta (1,6)GlcNAc as well as lactose in the coupled reaction, resulting in a significant decrease in the yield of desired sialylated trisaccharide. The conversion yield of the sialylation of Gal beta (1,6)GlcNAc could be improved by employing Bacillus circulans beta -galactosidase. (C) 2001 Elsevier Science Inc. All rights reserved.