描述
Dolichol phosphate is the most prevalent polyisoprenyl-glycosyl carrier found in mammals. It is involved in reactions such as the C-4 and O-mannosylation of proteins, the formation of glycosylphosphatidylinositol (GPI) anchors and the N-glycosylation of proteins. The chain length of eukaryotic dolichol molecules differs from 14 to 17 isoprene units in unicellular organisms like yeast whereas mammalian cells produce dolichol with 18-21 isoprene units. During the de novo synthesis of dolichol in eukaryotes, farnesyl pyrophosphate, a metabolite of cholesterol biosynthesis, is elongated by successive condensations to isopentenyl pyrophosphate molecules. These reactions are catalyzed by cis-isopentenyltransferases. After the polyisoprene pyrophosphate chain has reached its final length, both phosphate residues are released by mono- or pyrophosphatases. The isoprene unit of the polyprenol is then reduced by a nicotinamide adenine dinucleotide phosphate (NADPH)-dependent microsomal reductase. The final step in dolichol phosphate synthesis is catalyzed by dolichol kinase (DK1), an enzyme that transfers a phosphate from choline-phosphate cytidine triphosphate (CTP) to dolichol. Once synthesized, dolichol phosphate can react with cytosolic GDP-mannose in the endoplasmic reticulum membrane to form dolichyl phosphate D-mannose. A new inherited metabolic disorder, Dolichol kinase (DK1) deficiency has recently been discovered. Affected patients present with a very severe clinical phenotype, with death in early infancy. Symptoms include secondary microencephaly, dry, thin, parchmentlike skin, hyperkeratosis, minimal hair growth and muscular hypotonia. (PMID: 17273964) [HMDB]
InChI标识符
InChI=1S/C15H29O4P/c1-13(2)7-5-8-14(3)9-6-10-15(4)11-12-19-20(16,17)18/h7,9,15H,5-6,8,10-12H2,1-4H3,(H2,16,17,18)/b14-9+