Search results for "Glycosyl"
showing 10 items of 317 documents
Deficiency of the Cockayne syndrome B (CSB) gene aggravates the genomic instability caused by endogenous oxidative DNA base damage in mice.
2007
The Cockayne syndrome B protein (CSB) has long been known to be involved in the repair of DNA modifications that block the RNA polymerase in transcribed DNA sequences (transcription-coupled repair). Recent evidence suggests that it also has a more general role in the repair of oxidative DNA base modifications such as 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxoG). In mammalian cells, 8-oxoG is a substrate of the repair glycosylase OGG1. Mice without this enzyme accumulate 8-oxoG in the genome and have elevated spontaneous mutation rates. To elucidate the role of CSB in the prevention of mutations by oxidative DNA base damage, we have generated mice that are deficient in Csb or Ogg1 or both ge…
National, regional, and global trends in fasting plasma glucose and diabetes prevalence since 1980: systematic analysis of health examination surveys…
2011
Summary Background Data for trends in glycaemia and diabetes prevalence are needed to understand the effects of diet and lifestyle within populations, assess the performance of interventions, and plan health services. No consistent and comparable global analysis of trends has been done. We estimated trends and their uncertainties in mean fasting plasma glucose (FPG) and diabetes prevalence for adults aged 25 years and older in 199 countries and territories. Methods We obtained data from health examination surveys and epidemiological studies (370 country-years and 2·7 million participants). We converted systematically between different glycaemic metrics. For each sex, we used a Bayesian hier…
Rat mammary-gland transferrin: nucleotide sequence, phylogenetic analysis and glycan structure
1995
The complete cDNA for rat mammary-gland transferrin (Tf) has been sequenced and also the native protein isolated from milk in order to analyse the structure of the main glycan variants present. A lactating-rat mammary-gland cDNA library in lambda gt10 was screened with a partial cDNA copy of rat liver Tf and subsequently rescreened with 5′ fragments of the longest clones. This produced a 2275 bp insert coding for an open reading frame of 695 amino acid residues. This includes a 19-amino acid signal sequence and the mature protein containing 676 amino acids and one N-glycosylation site in the C-terminal domain at residue 490. Phylogenetic analysis was carried out using 14 translated Tf nucle…
Cohen syndrome is associated with major glycosylation defects
2014
International audience; Cohen syndrome (CS) is a rare autosomal recessive disorder with multisytemic clinical features due to mutations in the VPS13B gene, which has recently been described encoding a mandatory membrane protein involved in Golgi integrity. As the Golgi complex is the place where glycosylation of newly synthesized proteins occurs, we hypothesized that VPS13B deficiency, responsible of Golgi apparatus disturbance, could lead to glycosylation defects and/or mysfunction of this organelle, and thus be a cause of the main clinical manifestations of CS. The glycosylation status of CS serum proteins showed a very unusual pattern of glycosylation characterized by a significant accum…
Mouse Testican-2
2005
Mouse testican-2 was cloned, sequenced, and shown to be a proteoglycan with a multidomain structure closely similar to that of the human ortholog, previously described as a calcium binding extracellular matrix molecule of the BM-40/SPARC/osteonectin family (Vannahme, C., Schubel, S., Herud, M., Gosling, S., Hulsmann, H., Paulsson, M., Hartmann, U., and Maurer, P. (1999). J. Neurochem. 73, 12–20). Recombinant mouse testican-2 was used to prepare specific antibodies that allowed the detection of testican-2 in various brain structures but also in lung, testis, and in several endocrine glands. Although the testican-2 expressed in EBNA-293 cells carried both heparan sulfate and chondroitin/derma…
Role for calnexin and N-linked glycosylation in the assembly and secretion of hepatitis B virus middle envelope protein particles.
1998
ABSTRACT Unlike those of the S and the L envelope proteins, the functional role of the related M protein in the life cycle of the hepatitis B virus (HBV) is less understood. We now demonstrate that a single N glycan, specific for M, is required for efficient secretion of M empty envelope particles. Moreover, this glycan mediates specific association of M with the chaperone calnexin. Conversely, the N glycan, common to all three envelope proteins, is involved neither in calnexin binding nor in subviral particle release. As proper folding and trafficking of M need the assistance of the chaperone, the glycan-dependent association of M with calnexin may thus play a crucial role in the assembly …
Glycation alters ligand binding, enzymatic, and pharmacological properties of human albumin.
2015
Albumin, the major circulating protein in blood plasma, can be subjected to an increased level of glycation in a diabetic context. Albumin exerts crucial pharmacological activities through its drug binding capacity, i.e., ketoprofen, and via its esterase-like activity, allowing the conversion of prodrugs into active drugs. In this study, the impact of the glucose-mediated glycation on the pharmacological and biochemical properties of human albumin was investigated. Aggregation product levels and the redox state were quantified to assess the impact of glycation-mediated changes on the structural properties of albumin. Glucose-mediated changes in ketoprofen binding properties and esterase-lik…
Thermal aggregation of glycated bovine serum albumin
2010
International audience; Aggregation and glycation processes in proteins have a particular interest in medicine fields and in food technology. Serum albumins are model proteins which are able to self-assembly in aggregates and also sensitive to a non-enzymatic glycation in cases of diabetes. In this work, we firstly reported a study on the glycation and oxidation effects on the structure of bovine serum albumin (BSA). The experimental approach is based on the study of conformational changes of BSA at secondary and tertiary structures by FTIR absorption and fluorescence spectroscopy, respectively. Secondly, we analysed the thermal aggregation process on BSA glycated with different glucose con…
Glycosylamines of 4,6-O-butylidene-α-d-glucopyranose: synthesis and characterization of glycosylamines, and the crystal structure of 4,6-O-butylidene…
2002
A total of nine glycosylamines of 4,6-O-butylidene-α-D-glucopyranose were synthesized using primary amines having various groups in their ortho- or para-positions. Among these, six are monoglycosylamines, including one primary glycosylamine, and three are bis-glycosylamines. All these compounds were characterized by 1H, 1H–1H COSY, 1H–13C COSY and 13C NMR spectroscopy and FTIR spectra. The FAB mass spectra provided the molecular weights of the products by exhibiting the corresponding molecular ion peaks. The crystal structure of 4,6-O-butylidene-N-(o-chlorophenyl)-β-D-glucopyranosylamine revealed the C-1 glycosylation, the β-anomeric nature, and the 4C1 chair conformation of the saccharide …
Reversal of asymmetric induction in stereoselective strecker synthesis on galactosyl amine as the chiral matrix
1988
Abstract The reversal of the direction of asymmetric induction in Lewis acid catalyzed Strecker synthesis using the 2,3,4,6-tetra-O-pivaloyl-β-D-galactopyranosyl amine 1 is described. In isopropanol or tetrahydrofuran 1 had given ( R )-diastereomers of the corresponding α-amino nitriles preferably. However, in chloroform in the presence of heterogeneous zinc chloride the same auxiliary alternatively leads to an excess of the ( S )-diastereomers.