From oligosaccharides

While the majority of reported work concerning the sequencing of biomolecules by LC-MS has involved proteins, important information may also be obtained from oligosaccharides by employing a similar methodology to that described previously. 

Incomplete (N-linked) glycosylation prompts decreased in vivo activity due to more rapid hepatic clearance of the EPO molecule. Enzymatic removal of terminal sialic acid sugar residues from oligosaccharides exposes otherwise hidden galactose residues. These residues are then free to bind specific hepatic lectins, which promote EPO removal from the plasma. The reported plasma tm value for native EPO is 4-6 h. The tm for desialated EPO is 2 min. Comparison of native human EPO with its recombinant form produced in CHO cells reveals very similar glycosylation patterns. 

Although the initial velocity of the desorbed ions is difficult to measure, reported values generally are in the range of 400-1200 m s" The initial velocity is almost independent of the ionic mass but dependent on the matrix. [33,36-38,46,50,51] On the other hand, the initial ion velocity is not independent of the compound class, i.e., peptides show a behavior different from oligosaccharides. [51]... 

A. Oseltamivir inhibits neuraminidase, an enzyme that cleaves neuraminic acid from oligosaccharides. Neuraminidase activity aids the movement of viral particles through neuraminic acid-rich respiratory secretions and is required for the release of progeny virions. Inhibition of viral DNA polymerase is the mechanism of action of nucleoside analogue antiviral drugs. Interferons do stimulate the JAK-STAT signaling pathway but do not stimulate proliferation of immune cells. Ribavirin inhibits GTP synthesis, and the antiretroviral protease inhibitors (e.g., ritonavir) inhibit HIV protease. 

Fig. 3. —Proposed Structure of a Portion of theHemieellulosicXyloglucan of the Primary Cell-Wall of Dicots (After Albersheim5-64). [Heptasac-charide A and nonasaccharide B are derived from oligosaccharide C by the action of endo-(l—>4)-/ -D-glucanase at the bonds indicated by arrows. Pentasaccharide D is derived from "B by the combined action of a-L-fucosidase, a-D-xylosidase, and /J-D-glucosidase. A = L-arabinopyranose F = L-fucose G = D-glucose Gal = D-galactose X = D-xylose.]...

Cyclodextrin - A Naturally Occurring Cyclic Host Cyclodextrins are cyclic hosts made from oligosaccharides. They provide a hydrophobic microenvironment in an aqueous phase. 

Saksena R, Ma X, Kovac P. One-pot preparation of a series of glycoconjugates with predetermined antigen-carrier ratio from oligosaccharides that mimic the O-PS of Vibrio cholerae 0 1, serotype Ogawa. Carbohydr Res. 2003 338 2591-2603. 

Fig. 3. Mass spectral nomenclature for fragment ions from oligosaccharide derivatives.

The spikes are of two types. One type (haemagglutinin) has a vital role in the first stages of infection, the penetration of host cells. The second type of spike is made of an enzyme called sialidase, whose role is to help newly formed viruses escape from the host cell so that they can move on to infect other cells. As part of this process, sialidase cleaves off sialic acid from oligosaccharides (short chains of carbohydrate units). These sialidase spikes have clefts that contain an acti ve site, into which bound sialic acid (Structure 3.1) fits during the cleavage process. This active site... 

Sialidases such as the influenza neuraminidase are retaining enzymes that catalyze the hydrolysis of a-D-A -acetylneuraminic acids from oligosaccharides or glycolipids and glycoproteins. Inhibitors of these enzymes are of great interest since it has been shown that neuraminidase activity can correlate with virulence. ... 

L-Fucose liberated from oligosaccharides with a-L-fucosidase has been determined by measurement of the NADH formed following treatment with L-fucose dehydrogenase. ... 

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