K. Panneerselvam

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Direct utilization of mannose for glycoprotein biosynthesis has not been studied because cellular mannose is assumed to be derived entirely from glucose. However, animal sera contain sufficient mannose to force uptake through glucose-tolerant, mannose-specific transporters. Under physiological conditions this transport system provides 75% of the mannose for(More)
The concentration of D-mannose in serum is 20-50 micron, but its physiological significance for glycoprotein synthesis is unknown. Here, we show that the uptake of D-mannose by different mammalian cell lines involves a mannose-specific transporter(s) with a K(uptake) of about 30-70 micron and a V(max) which is probably sufficient to account for the bulk of(More)
Type I carbohydrate-deficient glycoprotein syndrome (CDGS) patients fail to add entire N-linked oligosaccharide chains to some serum glycoproteins. Here we show that four CDGS fibroblast cell lines have two related glycosylation abnormalities. First, they incorporate 3-10-fold less [3H] mannose into proteins, and, second, the size of the lipid-linked(More)
Alpha-mannosidase-II (alphaM-II) catalyzes the first committed step in the biosynthesis of complex asparagine-linked (N-linked) oligosaccharides (N-glycans). Genetic deficiency of alphaM-II should abolish complex N-glycan production as reportedly does inhibition of alphaM-II by swainsonine. We find that mice lacking a functional alphaM-II gene develop a(More)
We recently showed that a class of novel carboxylated N:-glycans was constitutively expressed on endothelial cells. Activated, but not resting, neutrophils expressed binding sites for the novel glycans. We also showed that a mAb against these novel glycans (mAbGB3.1) inhibited leukocyte extravasation in a murine model of peritoneal inflammation. To identify(More)
Covalent attachment of polyethylene glycol, PEGylation, has been shown to prolong the half-life and enhance the pharmacodynamics of therapeutic proteins. Current methods for PEGylation, which rely on chemical conjugation through reactive groups on amino acids, often generate isoforms in which PEG is attached at sites that interfere with bioactivity. Here,(More)
Mannose in N-linked oligosaccharides is assumed to be derived primarily from glucose through phosphomannose isomerase (PMI). The discovery of mammalian mannose-specific transporters that function at physiological concentrations suggested that mannose might directly contribute to oligosaccharide synthesis. To determine the relative contribution of glucose(More)
Indian students lack the skill of Self-regulated Learning (SRL) that is indispensable for lifelong learning. Current E-Learning systems provide content to the students as a whole, needing effort from the students to identify, discriminate and classify contents to be covered for particular topics. In this paper, a Learning Management System (LMS) is(More)
Congenital Disorders of Glycosylation (CDG) are human deficiencies in glycoprotein biosynthesis. Previous studies showed that 1 mM mannose corrects defective protein N-glycosylation in cultured fibroblasts from some CDG patients. We hypothesized that these CDG cells have limited GDP-mannose (GDP-Man) and that exogenous mannose increases the GDP-Man levels.(More)
Expert or knowledge-based systems are the most common type of AIM (artificial intelligence in medicine) system in routine clinical use. They contain medical knowledge, usually about a very specifically defined task, and are able to reason with data from individual patients to come up with reasoned conclusion. Although there are many variations, the(More)