Enzymatic Synthesis of Human Milk Fucosides alpha 1,2-Fucosyl para-Lacto-N-Hexaose and its Isomeric Derivatives

摘要

Enzymatic synthesis of para-lacto-N-hexaose and its isomeric structures as well as those alpha 1,2-fucosylated variants naturally occurring in human milk oligosaccharide (HMOs) was achieved using a sequential one-pot enzymatic system. Three glycosylation routes comprising bacterial glycosyl-transferases and corresponding sugar-nucleotide-generating enzymes were developed to facilitate efficient production of extended type-1 and type-2N-acetyllactosamine (LacNAc) backbones and hybrid chains. Further fucosylation efficiency of two alpha 1,2-fucosyltransferases on both type-1 and type-2 chains of the hexasaccharide was investigated to achieve practical synthesis of the fucosylated glycans. The availability of structurally defined HMOs offers a practical approach for investigating future biological applications.