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Chemical Compound Review

Man9GlcNAc     N-[(2R,3R,4R,5R)-6- [(2S,3S,4S,5S,6R)-4,5...

Synonyms: Man(9)glcnac, AC1MIX5H, 70158-33-7, N-Acetylglucosamine-mannose(9), Mannosyl(9)-N-acetylglucosamine
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Disease relevance of Man9GlcNAc

  • To explore the carbohydrate antigen for HIV-1 vaccine design, we have studied the binding of 2G12 to an array of HIV-1 high-mannose type oligosaccharides by competitive ELISAs and found that Man9GlcNAc is 210- and 74-fold more effective than Man5GlcNAc and Man6GlcNAc in binding to 2G12 [1].

High impact information on Man9GlcNAc

  • High resolution proton nuclear magnetic resonance analysis of the products shows that the order of removal of mannose from Man(9)GlcNAc is different from that of other alpha1, 2-mannosidases that remove four mannose from Man(9)GlcNAc [2].
  • In the present work, it is demonstrated that with a single mutation in its catalytic domain (Arg(273) --> Leu) the yeast endoplasmic reticulum alpha1,2-mannosidase acquires the ability to transform Man(9)GlcNAc to Man(5)GlcNAc [2].
  • When expressed in COS7 cells as a secreted protein A fusion protein, the catalytic domain of clone 16 displays alpha-1,2-mannosidase activity using [3H]mannose-labeled Man9GlcNAc as substrate, but the corresponding region of clone 4 is poorly secreted under identical conditions [3].
  • The absence of Man9GlcNAc2 to Man8GlcNAc2 trimming in S. pombe and elongation of the lipid precursor of Man9GlcNAc with both Man and Gal to form "galactomannans" provides a novel system for N-linked glycoprotein processing studies [4].
  • A novel alpha-mannosidase has been identified in rat liver endoplasmic reticulum (ER) which at neutral pH processes the Man9GlcNAc oligosaccharide of glycoproteins by specifically cleaving the terminal mannose residue of the alpha 1,6-linked chain to yield Man8GlcNAc, isomer C [5].

Biological context of Man9GlcNAc

  • Its amino acid sequence is homologous to the recently isolated cDNA from rabbit liver alpha-1,2 mannosidase which can transform Man9GlcNAc to Man5GlcNAc (Moremen, K. W., Schutzbach, J. S., Forsee, W. T., Neame, P., Bishoff, J., Lodish, H. F., and Robbins, P. W. (1990) Glycoconjugate J. 7, 401) [6].
  • Hydrolysis of defined isomers of IgM and bovine thyroglobulin Man6,7,8GlcNAc indicated that, for maximal alpha 1,2-mannosidase activity, only the alpha 1,2-linked terminal mannoses on the alpha 3 branch of the Man9GlcNAc precursor were dispensable [7].
  • Using oligosaccharide substrate (Glc1Man9GlcNAc or Man9GlcNAc), the medium of cells transformed with this plasmid showed an increase in alpha-mannosidase activity that was directly related to the increase in cell density, whereas no alpha-mannosidase activity was detected in cells transformed with vector alone [8].
  • Using methylation, gas chromatography, mass spectrometry and digestion with alpha-mannosidase, they were shown to be mainly typical oligomannosidic oligosaccharides of size classes Man5GlcNAc to Man9GlcNAc [9].

Anatomical context of Man9GlcNAc

  • In normal hepatocytes alpha 1-proteinase inhibitor was present in the cells as a 49,000 Mr high mannose type glycoprotein with oligosaccharide side chains having the composition Man9GlcNAc and Man8GlcNAc with the former in a higher proportion [10].
  • In addition to mannosidase IA (Tabas, I., and Kornfeld, S. (1979) J. Biol. Chem. 254, 11655-11663), a second alpha-1,2-mannosidase (mannosidase IB) can be prepared from Golgi membranes which is effective in converting Man9GlcNAc to Man5GlcNAc [11].
  • Therefore, the digestion of Man9GlcNAc inside the lysosome appears to follow a very specific pathway, since only nine intermediate compounds can be identified instead of the 38 possible isomers [12].

Associations of Man9GlcNAc with other chemical compounds

  • High resolution 1H NMR analysis of the Man8GlcNAc formed from Man9GlcNAc in the presence of the alpha-mannosidase of Fraction II showed only a single isomer with the following structure: (see formula; see text) This specific enzyme is most probably involved in processing of oligosaccharide during biosynthesis of mannoproteins [13].
  • Incubation of this preparation with labeled Man8GlcNAc and Man9GlcNAc in the presence of GDP-mannose followed by high pressure liquid chromatography showed the formation of Man9GlcNAc and Man10GlcNAc, respectively [14].
  • With four potential N-glycosylation sites, the clottable protein was found to contain 3.8% high-mannose glycan; and Man8GlcNAc and Man9GlcNAc were released upon endo-beta-N-acetylglucosaminidase hydrolysis [15].
  • When the [3H]mannose-labeled oligosaccharides of alpha 1-proteinase inhibitor, secreted by 1-deoxymannojirimycin-treated hepatocytes, were cleaved off by endoglucosaminidase H and analyzed by Bio-Gel P-4 chromatography, they eluted at the position of Man9GlcNAc, indicating that mannosidase I had been efficiently inhibited [16].
  • For the substrates with the GlcNAc structure at their reducing ends (Man5GlcNAc, Man6GlcNAc and Man9GlcNAc), the hydrolysis rate was remarkably increased: Man5GlcNAc was hydrolyzed 16 times faster than M5A, and Man2GlcNAc 40 times faster than Man9GlcNAc2 [17].

Gene context of Man9GlcNAc

  • H.p.l.c. of the included oligosaccharides showed that a Man9GlcNAc, rather than a Man8GlcNAc, intermediate was formed in mns1 cells [18].
  • In all three tissue types, units with 9 Man tended to accumulate in TSH beta-subunits, whereas Man-trimming from Man9GlcNAc to Man8GlcNAc proceeded more rapidly in TSH alpha-subunits, and in free alpha-subunits [19].
  • Man8GlcNAc and Man9GlcNAc from yeast invertase and from bovine thyroglobulin were purified by gel filtration and examined by high field 1H-NMR analysis [20].
  • In control cells, Man7GlcNAc was identified in the protein-bound oligosaccharides released with endo-beta-N-acetylglucosaminidase H, in addition to the expected Glc1-3Man9GlcNAc and Man9GlcNAc arising from processing of Glc3Man9GlcNAc [21].

Analytical, diagnostic and therapeutic context of Man9GlcNAc

  • The major neutral oligosaccharide eluted in the position of Man9GlcNAc when analyzed by high performance liquid chromatography whereas the minor species appeared to be 1-2 residues larger [22].
  • Using thin-layer chromatography to separate endo-beta-N-acetylglucosaminidase H-cleaved oligosaccharides, polymannosyl chains of different sizes, ranging from Man9GlcNAc to Man5GlcNAc, were separated [23].
  • [3H]mannose-labeled oligosaccharides from intracellular TSH and free alpha-subunits were analyzed by paper chromatography, and were predominantly Man9GlcNAc and Man8GlcNAc units both in the absence and presence of TRH [24].


  1. Binding of high-mannose-type oligosaccharides and synthetic oligomannose clusters to human antibody 2G12: implications for HIV-1 vaccine design. Wang, L.X., Ni, J., Singh, S., Li, H. Chem. Biol. (2004) [Pubmed]
  2. Mutation of Arg(273) to Leu alters the specificity of the yeast N-glycan processing class I alpha1,2-mannosidase. Romero, P.A., Vallée, F., Howell, P.L., Herscovics, A. J. Biol. Chem. (2000) [Pubmed]
  3. Two naturally occurring mouse alpha-1,2-mannosidase IB cDNA clones differ in three point mutations. Mutation of Phe592 to Ser592 is sufficient to abolish enzyme activity. Schneikert, J., Herscovics, A. J. Biol. Chem. (1995) [Pubmed]
  4. Glycoprotein synthesis in yeast. Early events in N-linked oligosaccharide processing in Schizosaccharomyces pombe. Ziegler, F.D., Gemmill, T.R., Trimble, R.B. J. Biol. Chem. (1994) [Pubmed]
  5. Demonstration that a kifunensine-resistant alpha-mannosidase with a unique processing action on N-linked oligosaccharides occurs in rat liver endoplasmic reticulum and various cultured cells. Weng, S., Spiro, R.G. J. Biol. Chem. (1993) [Pubmed]
  6. Glycoprotein biosynthesis in Saccharomyces cerevisiae. Isolation and characterization of the gene encoding a specific processing alpha-mannosidase. Camirand, A., Heysen, A., Grondin, B., Herscovics, A. J. Biol. Chem. (1991) [Pubmed]
  7. Glycoprotein biosynthesis in yeast: purification and characterization of the endoplasmic reticulum Man9 processing alpha-mannosidase. Ziegler, F.D., Trimble, R.B. Glycobiology (1991) [Pubmed]
  8. Production, purification and characterization of recombinant yeast processing alpha 1,2-mannosidase. Lipari, F., Herscovics, A. Glycobiology (1994) [Pubmed]
  9. Structural studies on the major oligosaccharides in a variant surface glycoprotein of Trypanosoma congolense. Savage, A., Geyer, R., Stirm, S., Reinwald, E., Risse, H.J. Mol. Biochem. Parasitol. (1984) [Pubmed]
  10. 1-deoxynojirimycin impairs oligosaccharide processing of alpha 1-proteinase inhibitor and inhibits its secretion in primary cultures of rat hepatocytes. Gross, V., Andus, T., Tran-Thi, T.A., Schwarz, R.T., Decker, K., Heinrich, P.C. J. Biol. Chem. (1983) [Pubmed]
  11. alpha-D-Mannosidases of rat liver Golgi membranes. Mannosidase II is the GlcNAcMAN5-cleaving enzyme in glycoprotein biosynthesis and mannosidases Ia and IB are the enzymes converting Man9 precursors to Man5 intermediates. Tulsiani, D.R., Hubbard, S.C., Robbins, P.W., Touster, O. J. Biol. Chem. (1982) [Pubmed]
  12. In vitro hydrolysis of oligomannosyl oligosaccharides by the lysosomal alpha-D-mannosidases. Michalski, J.C., Haeuw, J.F., Wieruszeski, J.M., Montreuil, J., Strecker, G. Eur. J. Biochem. (1990) [Pubmed]
  13. Characterization of a specific alpha-mannosidase involved in oligosaccharide processing in Saccharomyces cerevisiae. Jelinek-Kelly, S., Akiyama, T., Saunier, B., Tkacz, J.S., Herscovics, A. J. Biol. Chem. (1985) [Pubmed]
  14. Glycoprotein biosynthesis in Saccharomyces cerevisiae. Characterization of alpha-1,6-mannosyltransferase which initiates outer chain formation. Romero, P.A., Herscovics, A. J. Biol. Chem. (1989) [Pubmed]
  15. Molecular cloning and characterization of a hemolymph clottable protein from tiger shrimp (Penaeus monodon). Yeh, M.S., Huang, C.J., Leu, J.H., Lee, Y.C., Tsai, I.H. Eur. J. Biochem. (1999) [Pubmed]
  16. Secretion of high-mannose-type alpha 1-proteinase inhibitor and alpha 1-acid glycoprotein by primary cultures of rat hepatocytes in the presence of the mannosidase I inhibitor 1-deoxymannojirimycin. Gross, V., Steube, K., Tran-Thi, T.A., McDowell, W., Schwarz, R.T., Decker, K., Gerok, W., Heinrich, P.C. Eur. J. Biochem. (1985) [Pubmed]
  17. Studies on the substrate specificity of neutral alpha-mannosidase purified from Japanese quail oviduct by using sugar chains from glycoproteins. Oku, H., Hase, S. J. Biochem. (1991) [Pubmed]
  18. Disruption of the processing alpha-mannosidase gene does not prevent outer chain synthesis in Saccharomyces cerevisiae. Puccia, R., Grondin, B., Herscovics, A. Biochem. J. (1993) [Pubmed]
  19. Structures of high-mannose oligosaccharides of mouse thyrotropin: differential processing of alpha- versus beta-subunits of the heterodimer. Magner, J.A., Papagiannes, E. Endocrinology (1987) [Pubmed]
  20. Glycoprotein synthesis in yeast. Identification of Man8GlcNAc2 as an essential intermediate in oligosaccharide processing. Byrd, J.C., Tarentino, A.L., Maley, F., Atkinson, P.H., Trimble, R.B. J. Biol. Chem. (1982) [Pubmed]
  21. Transfer of nonglucosylated oligosaccharide from lipid to protein in a mammalian cell. Romero, P.A., Herscovics, A. J. Biol. Chem. (1986) [Pubmed]
  22. Structural analysis of the asparagine-linked oligosaccharides from three lysosomal enzymes of Dictyostelium discoideum. Evidence for an unusual acid-stable phosphodiester. Freeze, H.H., Yeh, R., Miller, A.L., Kornfeld, S. J. Biol. Chem. (1983) [Pubmed]
  23. Processing of N-linked oligosaccharides from precursor- to mature-form herpes simplex virus type 1 glycoprotein gC. Serafini-Cessi, F., Dall'Olio, F., Pereira, L., Campadelli-Fiume, G. J. Virol. (1984) [Pubmed]
  24. Structures of high-mannose and complex oligosaccharides of mouse TSH and free alpha-subunits after in vitro incubation of thyrotropic tissue with TRH. Magner, J.A., Miura, Y., Rubin, D., Kane, J. Endocr. Res. (1992) [Pubmed]
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