Mannose
From Wikipedia, the free encyclopedia
| Mannose | |
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| CAS number | [] |
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| 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 |
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Mannose is a sugar monomer of the aldohexose series of carbohydrates.
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[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
- ^ Direct utilization of mannose for mammalian glycoprotein biosynthesis. Oxford Journals, Life Sciences, Glycobiology, Volume 8, Number 3 Pp. 285-295
- ^ 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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