684269-07-6Relevant academic research and scientific papers
Convergent synthesis of homogeneous Glc1Man 9GlcNAc2-protein and derivatives as ligands of molecular chaperones in protein quality control
Amin, Mohammed N.,Huang, Wei,Mizanur, Rahman M.,Wang, Lai-Xi
, p. 14404 - 14417 (2011/10/19)
A detailed understanding of the molecular mechanism of chaperone-assisted protein quality control is often hampered by the lack of well-defined homogeneous glycoprotein probes. We describe here a highly convergent chemoenzymatic synthesis of the monoglucosylated glycoforms of bovine ribonuclease (RNase) as specific ligands of lectin-like chaperones calnexin (CNX) and calreticulin (CRT) that are known to recognize the monoglucosylated high-mannose oligosaccharide component of glycoproteins in protein folding. The synthesis of a selectively modified glycoform Gal1Glc 1Man9GlcNAc2-RNase was accomplished by chemical synthesis of a large N-glycan oxazoline and its subsequent enzymatic ligation to GlcNAc-RNase under the catalysis of a glycosynthase. Selective removal of the terminal galactose by a β-galactosidase gave the Glc1Man 9GlcNAc2-RNase glycoform in excellent yield. CD spectroscopic analysis and RNA-hydrolyzing assay indicated that the synthetic RNase glycoforms maintained essentially the same global conformations and were fully active as the natural bovine ribonuclease B. SPR binding studies revealed that the Glc1Man9GlcNAc2-RNase had high affinity to lectin CRT, while the synthetic Man9GlcNAc 2-RNase glycoform and natural RNase B did not show CRT-binding activity. These results confirmed the essential role of the glucose moiety in the chaperone molecular recognition. Interestingly, the galactose-masked glycoform Gal1Glc1Man9GlcNAc2-RNase also showed significant affinity to lectin CRT, suggesting that a galactose β-1,4-linked to the key glucose moiety does not significantly block the lectin binding. These synthetic homogeneous glycoprotein probes should be valuable for a detailed mechanistic study on how molecular chaperones work in concert to distinguish between misfolded and folded glycoproteins in the protein quality control cycle.
A facile synthesis of mannose tri- and tetrasaccharide repeating units of fungal cell-wall polysaccharide from Microsporum and Trychophyton species
Zhu, Yuliang,Kong, Fanzuo
, p. 1219 - 1226 (2007/10/03)
A facile synthesis of the trisaccharide α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→6) -α-D-mannopyranose and the tetrasaccharide α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→6) -α-D-mannopyranosyl-(1→6)-D-mannopyranose, the repeating units of fungal cell-wall polysaccharide from Microsporum gypseum and Trychophyton, was achieved using α(1→2)-linked disaccharide imidate as the donor. The disaccharide imidate was prepared from the self-condensation of 3,4,6-tri-O-benzoyl-1,2-O-allyloxyethylidene-β-D-mannopyranose.
Concise and effective synthesis of α(1→2)-linked manno- and rhamnopyranosyl oligosaccharides and related antigenic factor 4 and dominant of antigenic factor 6
Zhu,Kong
, p. 1783 - 1787 (2007/10/03)
A highly concise and effective synthesis of α(1→2)linked manno- and rhamnopyranosyl oligosaccharides was achieved via TMSOTf promoted condensation of the corresponding benzoylated monosaccharide alkyl orthoester, α(1→2)-Linked mannosyl tetra- and octasaccharide, rhamnosyl tetrasaccharide, antigenic factor 4, and dominant of antigenic factor 6 were readily synthesized by the new method.
