Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Medicine and Health Sciences
Acute Modulation Of Sugar Transport In Brain Capillary Endothelial Cell Cultures During Activation Of The Metabolic Stress Pathway, Anthony Cura, Anthony Carruthers
Acute Modulation Of Sugar Transport In Brain Capillary Endothelial Cell Cultures During Activation Of The Metabolic Stress Pathway, Anthony Cura, Anthony Carruthers
Anthony J. Cura
GLUT1-catalyzed equilibrative sugar transport across the mammalian blood-brain barrier is stimulated during acute and chronic metabolic stress; however, the mechanism of acute transport regulation is unknown. We have examined acute sugar transport regulation in the murine brain microvasculature endothelial cell line bEnd.3. Acute cellular metabolic stress was induced by glucose depletion, by potassium cyanide, or by carbonyl cyanide p-trifluoromethoxyphenylhydrazone, which reduce or deplete intracellular ATP within 15 min. This results in a 1.7-7-fold increase in V(max) for zero-trans 3-O-methylglucose uptake (sugar uptake into sugar-free cells) and a 3-10-fold increase in V(max) for equilibrium exchange transport (intracellular [sugar] = extracellular [sugar]). …
Dolichol-Linked Oligosaccharide Selection By The Oligosaccharyltransferase In Protist And Fungal Organisms, Daniel Kelleher, Sulagna Banerjee, Anthony Cura, John Samuelson, Reid Gilmore
Dolichol-Linked Oligosaccharide Selection By The Oligosaccharyltransferase In Protist And Fungal Organisms, Daniel Kelleher, Sulagna Banerjee, Anthony Cura, John Samuelson, Reid Gilmore
Anthony J. Cura
The dolichol-linked oligosaccharide Glc3Man9GlcNAc2-PP-Dol is the in vivo donor substrate synthesized by most eukaryotes for asparagine-linked glycosylation. However, many protist organisms assemble dolichol-linked oligosaccharides that lack glucose residues. We have compared donor substrate utilization by the oligosaccharyltransferase (OST) from Trypanosoma cruzi, Entamoeba histolytica, Trichomonas vaginalis, Cryptococcus neoformans, and Saccharomyces cerevisiae using structurally homogeneous dolichol-linked oligosaccharides as well as a heterogeneous dolichol-linked oligosaccharide library. Our results demonstrate that the OST from diverse organisms utilizes the in vivo oligo saccharide donor in preference to certain larger and/or smaller oligosaccharide donors. Steady-state enzyme kinetic experiments reveal that the binding affinity of the tripeptide …