title: The beta-phosphoro[35S]thioate analogue of UDP-Glc is efficiently utilized by the glucose phosphotransferase and is relatively resistant to hydrolytic degradation.
abstract: The beta-phosphoro[35S]thioate analogue of UDP-glucose ((beta-35S)UDP-Glc) is utilized with approximately the same efficiency as the parent compound by the UDP-glucose:glycoprotein glucose-1-phosphotransferase (glucosyltransferase), which catalyzes the transfer of alpha Glc-1-P from UDP-Glc to mannose-containing oligosaccharides on acceptor glycoproteins. The same endogenous acceptor glycoproteins are labeled by the glucosyltransferase using [beta-32P]UDP-Glc and (beta-35S)UDP-Glc. However, in liver homogenates, incorporation from [beta-32P]UDP-Glc ceases to increase after about 4 min of incubation, while incorporation from (beta-35S)UDP-Glc persists for at least 1 h. This difference is due to an approx. 10-fold slower hydrolytic rate for the phosphorothioate analogue than for the parent compound, a finding similar to previous work showing that a variety of nucleases and phosphodiesterases are less efficient in cleaving phosphorothioate DNA than the native polymer.
authors.affiliation: Department of Cell Biology and Anatomy, University of Alabama 35294.
authors.forename: R B
authors.initials: RB
authors.lastname: Marchase
authors.forename: A M
authors.initials: AM
authors.lastname: Saunders
authors.forename: A A
authors.initials: AA
authors.lastname: Rivera
authors.forename: J M
authors.initials: JM
authors.lastname: Cook
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005958:Glucosephosphates / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D008970:Molecular Weight; D010761:Phosphorus Radioisotopes; D010770:Phosphotransferases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013462:Sulfur Radioisotopes; D017855:Transferases (Other Substituted Phosphate Groups); D014532:Uridine Diphosphate Glucose / Q000031:analogs & derivatives / Q000378:metabolism*; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*
chemical_list: D005958:Glucosephosphates; D010761:Phosphorus Radioisotopes; D013462:Sulfur Radioisotopes; D014539:Uridine Diphosphate Sugars; C054208:uridine phosphate-beta-thiophosphate glucose; C031590:glucose-1-phosphate; D010770:Phosphotransferases; D017855:Transferases (Other Substituted Phosphate Groups); C037061:UDPglucose-glycoprotein glucose-1-phosphotransferase; D014532:Uridine Diphosphate Glucose