All eukaryotic cells share a common core pentasaccharide, Man3GlcNAc2 （M3）, which is found in both dolichol-linked oligosaccharides （DLOs） and N-linked glycoproteins. A pentasaccharide M3 can be elongated and elab...All eukaryotic cells share a common core pentasaccharide, Man3GlcNAc2 （M3）, which is found in both dolichol-linked oligosaccharides （DLOs） and N-linked glycoproteins. A pentasaccharide M3 can be elongated and elaborated by various glycosyltransferases and is thus considered as the key intermediate in the in vitro synthetic pathway of N-glycans. In this review, we describe the progresses in the preparation of M3 by chemical and chemoenzymatic methods. We first draw a brief schematic view of the typical N-glycan biological pathway and then focus on the requirements and challenges in obtaining core pentasaccharides. Representative methods and recent reported findings, especially research progress in chemoenzymatic synthesis, are highlighted. In addition, the opportunities in exploiting novel methods for constructing N-glycans, as well as their applications, are discussed.展开更多
β-Glucan exhibits various beneficial biological activities including immunostimulation.This polysaccha-ride is present in the cell wall of microorganisms including the yeast Saccharomyces cerevisiae.Although vegetati...β-Glucan exhibits various beneficial biological activities including immunostimulation.This polysaccha-ride is present in the cell wall of microorganisms including the yeast Saccharomyces cerevisiae.Although vegetative yeast cells are used as dietary supplements,β-glucan in the vegetative cell wall is covered with mannan.During nutrient starvation,yeast cells differentiate into dormant cell spores.β-Glucan is also present in the spore wall,but spores have been poorly studied as application tools.The spore wall consists of four layers andβ-glucan forms the third layer from the outside.However,unlike vegeta-tive cells,theβ-glucan layer can be exposed to the cell surface in spores by genetic manipulation.For example,chs3Δmutant spores exhibit such a spore wall configuration.Dectin-1 is the primary receptor forβ-glucan in mammals and,its activation induces phagocytosis and proinflammatory cytokine secre-tions.We found that chs3Δspores are phagocytosed in mammalian cells in a manner dependent on dectin-1 and induce higher levels of TNF-αand IL-6 than vegetative cells.Our results demonstrate that chs3Δspores areβ-glucan particles with immunostimulatory activities.Thus,they would be attractive materials for application in the food industry.展开更多
基金supported by the National Natural Science Foundation of China(No. 21576118)Fundamental Research Funds for the Central Universities(Nos. JUSRP51629B, JUSRP11727)+1 种基金Open Project Program of Key Laboratory of Carbohydrate Chemistry and Biotechnology(No. KLCCB-KF201604)Program of Introducing Talents of Discipline to Universities (No. 111-2-06)
文摘All eukaryotic cells share a common core pentasaccharide, Man3GlcNAc2 （M3）, which is found in both dolichol-linked oligosaccharides （DLOs） and N-linked glycoproteins. A pentasaccharide M3 can be elongated and elaborated by various glycosyltransferases and is thus considered as the key intermediate in the in vitro synthetic pathway of N-glycans. In this review, we describe the progresses in the preparation of M3 by chemical and chemoenzymatic methods. We first draw a brief schematic view of the typical N-glycan biological pathway and then focus on the requirements and challenges in obtaining core pentasaccharides. Representative methods and recent reported findings, especially research progress in chemoenzymatic synthesis, are highlighted. In addition, the opportunities in exploiting novel methods for constructing N-glycans, as well as their applications, are discussed.
基金This work is supported by National First-class Discipline Program of Light Industry Technology and Engineering(LITE2018-015)Project 111(111-2-06)+2 种基金Collaborative Innovation Center of jiangsu Modern Industrial Fermentation,International Joint Research Laboratory for production of therapeutic glycoproteins at Jiangnan University to X.-D.GaoFundamental Research Funds for the Central Universities to H.Nakanishi(JUSRP51629B)National Natural Science Foundation of China grants to H.Nakanishi(32071467)and X.-D.Gao(21778023).
文摘β-Glucan exhibits various beneficial biological activities including immunostimulation.This polysaccha-ride is present in the cell wall of microorganisms including the yeast Saccharomyces cerevisiae.Although vegetative yeast cells are used as dietary supplements,β-glucan in the vegetative cell wall is covered with mannan.During nutrient starvation,yeast cells differentiate into dormant cell spores.β-Glucan is also present in the spore wall,but spores have been poorly studied as application tools.The spore wall consists of four layers andβ-glucan forms the third layer from the outside.However,unlike vegeta-tive cells,theβ-glucan layer can be exposed to the cell surface in spores by genetic manipulation.For example,chs3Δmutant spores exhibit such a spore wall configuration.Dectin-1 is the primary receptor forβ-glucan in mammals and,its activation induces phagocytosis and proinflammatory cytokine secre-tions.We found that chs3Δspores are phagocytosed in mammalian cells in a manner dependent on dectin-1 and induce higher levels of TNF-αand IL-6 than vegetative cells.Our results demonstrate that chs3Δspores areβ-glucan particles with immunostimulatory activities.Thus,they would be attractive materials for application in the food industry.
