通过酶促过程合成寡糖提供了将寡糖推向药物研究前沿的潜力,部分原因在于方便和可扩展的反应方案。糖合酶是一类新兴的突变酶,能够以高产率合成糖苷键。我们报告了一种由大肠杆菌 β-半乳糖苷酶的点突变产生的新糖合酶,该酶将 α-半乳糖基氟与芳基糖苷缩合形成 β-(1,6) 糖苷键。酶内靠近活性位点的进一步点突变显着提高了产量。关键词:糖基转移,糖合酶,酶促寡糖合成。四氢恶嗪、异法米明、亚氨基蔗糖、糖苷酶抑制剂。 [Traduit par la Redaction]
β-d-Gal-(1→4)-β-d-Glc-OC6H4NO2-p and its isomers (β-d-Gal-(l→3)-β-d-GIc-OC6H4NO2-p and β-d-Gal-(1→6)-β-d-Glc-OC6H4NO2-p) were synthesized from lactose and β-d-Glc-OC6H4NO2-p, using transglycosylation by the β-d-galactosidase from Bacillus circulans. This reaction was efficient enough for us to do a one-pot preparation of galactosyl-glucoside from lactose. The order of the production of the transfer products was (1→4) ≫ (1→3) > (1→6) in the initial stage of the reaction, and the same relationship was observed for the hydrolytic rate toward the three galactosyl-glucosides. The production of (1→4)- and (1→3)-linkages greatly decreased during the subsequent reaction and much more of the (1→6)- than of the (1→4)- and (1→3)-transfer products was found in the later stage of the reaction.
On expanding the repertoire of glycosynthases: Mutant β-galactosidases forming β-(1,6)-linkages
作者:David L Jakeman、Stephen G Withers
DOI:10.1139/v02-077
日期:2002.8.1
Oligosaccharidesynthesis by enzymatic processes offers the potential for thrusting oligosaccharides to the forefront of pharmaceutical research, in part, due to expedient and scalable reaction protocols. Glycosynthases are an emerging class of mutant enzymes capable of synthesizing glycosidic linkages in high yield. We report a new glycosynthase enzyme generated by a point mutation of E. coli β-galactosidase
通过酶促过程合成寡糖提供了将寡糖推向药物研究前沿的潜力,部分原因在于方便和可扩展的反应方案。糖合酶是一类新兴的突变酶,能够以高产率合成糖苷键。我们报告了一种由大肠杆菌 β-半乳糖苷酶的点突变产生的新糖合酶,该酶将 α-半乳糖基氟与芳基糖苷缩合形成 β-(1,6) 糖苷键。酶内靠近活性位点的进一步点突变显着提高了产量。关键词:糖基转移,糖合酶,酶促寡糖合成。四氢恶嗪、异法米明、亚氨基蔗糖、糖苷酶抑制剂。 [Traduit par la Redaction]
Glycosyl Azides – An Alternative Way to Disaccharides
good yields. The versatility of glycosylazides was demonstrated in the synthesis of five disaccharides– two of them are described for the first time. All the reactions were highly regioselective, yielding β(16) isomers. β-Galactosidase from E. coli proved to have the best synthetic capabilities. The present study shows that glycosylazides are a valuable alternative to common p-nitrophenyl glycoside