BACKGROUND Hemoglobin A1c (HbA1c) is the predominant diagnostic tool for diabetes diagnosis and progression. However, it has proven to be insensitive at pre-diabetic threshold values. O-linked-β-N-acetylglucosamine (O-GlcNAc) modification has emerged as a sensitive biomarker. The purpose of this study was to explore the sensitivity of O-GlcNAc expression as a potential marker of early metabolic...

BACKGROUND Hypoglycemia is associated with increased mortality rate in patients with diabetes. The underlying mechanisms may involve reduced myocardial tolerance to ischemia and reperfusion (IR) or reduced capacity for ischemic preconditioning (IPC). As IPC is associated with increased myocardial glucose uptake (MGU) during reperfusion, cardioprotection is linked to glucose metabolism possibly ...

A series of N-acetyl-chitooligosaccharides (GlcNAc)(1-6) have been studied by a nuclear magnetic resonance (NMR) method, diffusion ordered spectroscopy (DOSY). DOSY has also been applied to two additional synthetic related oligosaccharides [GlcNH(2)-(GlcNAc)(4) and GlcNH(2)-(GlcNAc)(2)-GlcNAcSO(3)Na]. A plot of the log of the determined diffusion coefficients (logD) of (GlcNAc)(n) versus the lo...

The clearance of apoptotic cells is important to maintain tissue homeostasis. The engulfment of apoptotic cells is performed by professional phagocytes, such as macrophages, and also by non-professional phagocytes, such as mesenchymal cells. Here, we show that vimentin, a cytoskeletal protein, functions as an engulfment receptor on neighboring phagocytes, which recognize O-linked β-N-acetylgluc...

The endochitinase from barley is the archetypal enzyme for a large class of plant-derived antifungal chitinases. The X-ray structure was solved previously in our laboratory and a mechanism of action proposed based on structural considerations. In this manuscript we report the use of a defined soluble substrate, 4-methylumbelliferyl beta-N,N',N"-triacetylchitotrioside, to characterize kinetic pa...

O-linked N-acetylglucosaminylation (O-GlcNAc) is a regulatory post-translational modification of nucleo-cytoplasmic proteins that has a complex interplay with phosphorylation. O-GlcNAc has been described as a nutritional sensor, the level of UDP-GlcNAc that serves as a donor for the uridine diphospho-N-acetylglucosamine:polypeptide beta-N-acetyl-glucosaminyltransferase being regulated by the ce...

The chiR gene of Serratia marcescens 2170, encoding a LysR-type transcriptional activator, was identified previously as an essential factor for expression of chitinases and a chitin-binding protein, CBP21. To identify other genes that are essential for chitinase production, transposon mutagenesis with mini-Tn5Km1 was carried out, and 25 mutants that were unable to produce chitinases and CBP21 w...

Signal transduction from the insulin receptor to downstream effectors is attenuated by phosphorylation at a number of Ser/Thr residues of insulin receptor substrate-1 (IRS-1) resulting in resistance to insulin action, the hallmark of type II diabetes. Ser/Thr residues can also be reversibly glycosylated by O-linked -N-acetylglucosamine (O-GlcNAc) monosaccharide, a dynamic posttranslational modi...

Beta-O-linked N-acetylglucosamine (O-GlcNAc) is an abundant modification of cytosolic and nuclear proteins that occurs in metazoans. O-GlcNAc is dynamically processed by a unique set of enzymes that actively add and remove the modification. Functionally, O-GlcNAc appears to regulate protein stability, subcellular localization and protein-protein interactions. The modification often acts in a re...