Xylulose 5-phosphate
- Xylulose -5-P
- Xu -5-P
- X5P
- ( 2,3,5 -trihydroxy -4- oxopentyl ) dihydrogen phosphate (IUPAC)
- C5H11O8P
- C5H9O8P2 ( deprotonated, physiological form)
- C5H10NaO8P (sodium salt)
- 60802-29-1
- 105931-44-0 (sodium salt)
Fixed
Sodium salt
Template: Infobox chemical / molecular formula search available
Xylulose -5-phosphate is phosphorylated at the C5 atom of the form of the pentose is a xylulose Stoffwechselintermediat many organisms. In nature only comes before the D-isomer.
Importance
Xylulose -5-phosphate ( XP5 ) is an important intermediate in the pentose phosphate pathway and may be epimerized from ribulose -5-phosphate therein. This reaction catalyzes a ribulose phosphate 3- epimerase. Xylulose -5-phosphate and ribose -5-phosphate is then converted by a transketolase to sedoheptulose 7-phosphate and glyceraldehyde -3-phosphate in the pentose phosphate pathway.
In addition, xylulose -5-phosphate has a function as a signaling molecule. It is produced in the pentose phosphate pathway, which takes place reinforced with high blood sugar levels in the liver - as well as glycolysis. There XP5 stimulates protein phosphatase 2A ( PP2A ), which dephosphorylates the bifunctional enzyme PFKFB. In this form, the kinase function is activated, resulting in fructose -2 ,6 -bisphosphate is increased. In the result, the glycolysis takes place reinforced, it makes a lot pyruvate and acetyl -CoA.
Simultaneously PP2A dephosphorylates a transcription factor, the carbohydrate - responsive element -binding protein ChREBP which is activated thereby. ChREBP stimulating the reading of the genes for lipid synthesis and fatty acid synthesis to begin.
Accordingly, in the combination of acetyl -CoA arising from the glycolytic and pentose phosphate pathway in the NADPH required in the formation of fatty acids. This excess glucose is used as a result of a good diet to build up of fats.