Mannose

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Mannose
Identifiers
CAS number [31103-86-3]
PubChem 18950
MeSH Mannose
Properties
Molecular formula C6H12O6
Molar mass 180.156 g mol-1
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox references
D and L straight-chain forms of mannose drawn using Fischer projections.

Mannose is a sugar monomer of the aldohexose series of carbohydrates.

Contents

[edit] Metabolism

Mannose is not well metabolized in humans.[1] Therefore, it does not significantly enter the carbohydrate metabolism when taken orally, and although traces of exogeneously introduced mannose have been detected in all body tissues, using radioactive markers, in a well hydrated mammal, although further studies are necessary, 90% of mannose ingested is excreted unconverted into the urine within 30 - 60 minutes, with 99% of the remainder being excreted within the following 8 hours. There is no significant increase in blood-glucose levels during this time.

Mannose is present in numerous glycoconjugates including N-linked glycosylation of proteins. C-mannosylation is also abundant and can be found in collage-like regions. Mannose is a C2 epimer of glucose and displays a 4C1 pucker in the solution ring form.

Recombinant proteins produced in yeast may be subject to mannose addition in patterns different from those used by mammalian cells[2]. This difference in recombinant proteins from those normally produced in mammalian organisms may influence the effectiveness of vaccines.

[edit] Formation

Mannose can be formed by the oxidation of mannitol.

It can also be formed from D-glucose in the Lobry-de Bruyn-van Ekenstein transformation

[edit] Etymology

The root of both "mannose" and "manitol" is manna, which the Bible records as the food supplied to the Israelites during their journey through the Sinai Peninsula. Manna is a sweet secretion of several trees and shrubs, such as Fraxinus ornus.

[edit] Configuration

The fact that D-mannose has the same configuration at its penultimate carbon as D-glyceraldehyde is unsurprising as that is what defines the dextro classification. However, mannose differs from D-glucose by inversion of the C2 chiral center. This apparently simple change leads to the drastically different chemistry of the two hexoses, as it does the remaining six aldohexoses.

[edit] See also

[edit] References

  1. ^ Direct utilization of mannose for mammalian glycoprotein biosynthesis. Oxford Journals, Life Sciences, Glycobiology, Volume 8, Number 3 Pp. 285-295
  2. ^ Vlahopoulos S, Gritzapis AD, Perez SA, Cacoullos N, Papamichail M, Baxevanis CN. Mannose addition by yeast Pichia Pastoris on recombinant HER-2 protein inhibits recognition by the monoclonal antibody herceptin. Vaccine. 2009 Jun 8. [Epub ahead of print]PMID: 19520203

[edit] External links

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