Biomaterial Database

Mammalian glycosyltransferases prefer glycosyl phosphoryl dolichols rather than glycosyl phosphoryl polyprenols as substrates for oligosaccharyl synthesis. 1994

C D'Souza-Schorey, and K R McLachlan, and S S Krag, and A D Elbein

Department of Biochemistry, University of Arkansas for Medical Sciences, Little Rock 72205.

We have studied the effectiveness of polyprenyl-P-mannose and polyprenol-P-glucose as donor substrates for the dolichyl-P-mannose:Man5(GlcNAc)2-PP-dolichol mannosyltransferase and the dolichyl-P-glucose:Man9(GlcNAc)2-PP-dolichol glucosyltransferase, respectively. The polyprenol moiety differs from dolichol only in the unsaturation of the terminal isoprene unit of the molecule. Based on the kinetics of the reactions, we have found that both glycosyltransferases have higher apparent Kms and lower apparent Vmaxs using polyprenyl-P-monosaccharides as substrates rather than the dolichyl-P-monosaccharides. The products formed with the polyprenyl-P-sugars were the same as those formed by the dolichol-linked sugars, indicating that the polyprenol substrates could be utilized by the glycosyltransferases in vitro. The results also indicate that the dolichyl-P-sugars and the polyprenyl-P-sugars compete for the same binding site on the enzyme. These findings are significant in terms of understanding the glycosylation phenotypes of Chinese hamster ovary cell mutants of the Lec9 complementation group, which lack the ability to convert polyprenol into dolichol.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008364	Mannosyltransferases	Enzymes that catalyze the transfer of mannose from a nucleoside diphosphate mannose to an acceptor molecule which is frequently another carbohydrate. The group includes EC 2.4.1.32, EC 2.4.1.48, EC 2.4.1.54, and EC 2.4.1.57.	Mannosyltransferase
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009844	Oligosaccharides	Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.	Oligosaccharide
D011103	Polyisoprenyl Phosphate Monosaccharides	These compounds function as activated monosaccharide carriers in the biosynthesis of glycoproteins and oligosaccharide phospholipids. Obtained from a nucleoside diphosphate sugar and a polyisoprenyl phosphate.	Isoprenoid Phosphate Monosaccharides,Monosaccharides, Isoprenoid Phosphate,Monosaccharides, Polyisoprenyl Phosphate,Phosphate Monosaccharides, Isoprenoid,Phosphate Monosaccharides, Polyisoprenyl
D002240	Carbohydrate Sequence	The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.	Carbohydrate Sequences,Sequence, Carbohydrate,Sequences, Carbohydrate
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004287	Dolichol Monophosphate Mannose	A lipophilic glycosyl carrier of the monosaccharide mannose in the biosynthesis of oligosaccharide phospholipids and glycoproteins.	Dolichyl Mannopyranosyl Phosphate,Dolichyl Mannosyl Phosphate,Mannolipid,Mannosyl Phosphoryl Dolichol,D-Mannopyranosyldolichyl,Dolicholphosphate Mannose,Dolichyl Alpha-D-Mannopyranosyl Phosphate,Alpha-D-Mannopyranosyl Phosphate, Dolichyl,D Mannopyranosyldolichyl,Dolichol, Mannosyl Phosphoryl,Dolichyl Alpha D Mannopyranosyl Phosphate,Mannopyranosyl Phosphate, Dolichyl,Mannose, Dolichol Monophosphate,Mannose, Dolicholphosphate,Mannosyl Phosphate, Dolichyl,Monophosphate Mannose, Dolichol,Phosphate, Dolichyl Alpha-D-Mannopyranosyl,Phosphate, Dolichyl Mannopyranosyl,Phosphate, Dolichyl Mannosyl,Phosphoryl Dolichol, Mannosyl
D005964	Glucosyltransferases	Enzymes that catalyze the transfer of glucose from a nucleoside diphosphate glucose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.	Glucosyltransferase
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster