Human milk oligosaccharides(HMOs)are very distinctive components in human milk and are beneficial for infant health.Lacto-N-biose I(LNB)is the core structural unit of HMOs,which could be used for the synthesis of othe...Human milk oligosaccharides(HMOs)are very distinctive components in human milk and are beneficial for infant health.Lacto-N-biose I(LNB)is the core structural unit of HMOs,which could be used for the synthesis of other HMOs.In this study,an ATP-free in vitro synthetic enzymatic biosystem contained four thermostable enzymes(alpha-glucan phosphorylase from Thermococcus kodakarensis,UDP-glucose-hexose-1-phosphate uridylyltransferase from Thermotoga maritima,UDP-glucose 4-epimerase from T.maritima,lacto-N-biose phosphorylase from Clostridium thermobutyricum)were constructed for the biosynthesis of LNB from starch and N-acetylglucosamine(GlcNAc).Under the optimal conditions,0.75 g/L and 2.23 g/L LNB was produced from 1.1 g/L and 4.4 g/L GlcNAc and excess starch,with the molar yield of 39%and 29%based on the GlcNAc concentration,respectively,confirming the feasibility of this in vitro synthetic enzymatic biosystem for LNB synthesis and shedding light on the biosynthesis of other HMOs using LNB as the core structural unit from low cost polysaccharides.展开更多
基金the National Key Research and Development Program of China(2021YFC2102300)the National Natural Science Foundation of China(Grant number 32022044)the cooperation fund with Shandong Runde Biotechnology Co.,LTD.
文摘Human milk oligosaccharides(HMOs)are very distinctive components in human milk and are beneficial for infant health.Lacto-N-biose I(LNB)is the core structural unit of HMOs,which could be used for the synthesis of other HMOs.In this study,an ATP-free in vitro synthetic enzymatic biosystem contained four thermostable enzymes(alpha-glucan phosphorylase from Thermococcus kodakarensis,UDP-glucose-hexose-1-phosphate uridylyltransferase from Thermotoga maritima,UDP-glucose 4-epimerase from T.maritima,lacto-N-biose phosphorylase from Clostridium thermobutyricum)were constructed for the biosynthesis of LNB from starch and N-acetylglucosamine(GlcNAc).Under the optimal conditions,0.75 g/L and 2.23 g/L LNB was produced from 1.1 g/L and 4.4 g/L GlcNAc and excess starch,with the molar yield of 39%and 29%based on the GlcNAc concentration,respectively,confirming the feasibility of this in vitro synthetic enzymatic biosystem for LNB synthesis and shedding light on the biosynthesis of other HMOs using LNB as the core structural unit from low cost polysaccharides.
