background: sialic acid is a component of serum that is elevated in diseases such as diabetes and certain malignancies.  the normal range of ssa concentration and serum neuraminidase activity in different populations are varied, probably due to racial differences.   objective: the purpose of the present study was to obtain the average ssa concentration and serum neuraminidase activity, in an ir...

During the infection cycle of influenza virus, progeny virions bud from the plasma membrane of infected cells. At that point they are potentially immobilised because of interactions between the viral haemagglutinin and sialic acid which is found in glycoconjugates on the cell surface and on glycoproteins of the virus itself Neuraminidase inhibitors might therefore be expected to have an antivir...

Crystallographic studies of neuraminidase-sialic acid complexes indicate that sialic acid is distorted on binding the enzyme. Three arginine residues on the enzyme interact with the carboxylate group of the sugar which is observed to be equatorial to the saccharide ring as a consequence of its distorted geometry. The glycosidic oxygen is positioned within hydrogen-bonding distance of Asp-151, i...

Angiotensin converting enzyme (dipeptidyl carboxypeptidase, kininase II; EC 3.4.15.1), is a membrane bound glycoprotein, playing an important role in the renin-aldosterone system. The enzyme contains a carbohydrate moiety, consisting of fucose, mannose, galactose, N-acetylglucosamine and N-acetylneuraminic acid. Treatment with neuraminidase (EC 3.2.1.18) removes sialic acid from the molecule. T...

Influenza virus neuraminidase inhibitors (NAIs), including oseltamivir, zanamivir and peramivir, are important antivirals for the treatment and prophylaxis of influenza. Increasing use of NAIs brings into focus the risk of drug resistance. The problem of resistance is of high clinical and epidemiological importance. There are generally three levels of antiviral resistance according to the way t...

BACKGROUND Neuraminidase, one of the two surface glycoproteins of influenza virus, cleaves terminal sialic acid residues from glycolipids or glycoproteins. Its crystal structure is known at high resolution, but the mechanism of glycosyl hydrolysis remains unclear. RESULTS We have determined the crystal structure at 1.8 A resolution of two complexes of influenza B/Beijing neuraminidase contain...

Mild digestion of isolated adipose tissue cells with Closfridium perjringens neuraminidase (10 to 20 mpg of purified enzyme per ml, 15 min at 37”) results in enhanced glucose transport by these cells. This effect appears to mimic closely the physiological effect of insulin on glucose transport by normal cells, and there is evidence to suggest that these two apparently different stimuli may affe...

We present here the three-dimensional structure of neuraminidase (E.C. 3.2.1.18) from influenza virus A/Tern/Australia/G70c/75 (N9), determined by the method of multiple isomorphous replacement, and the structure of the neuraminidase complexed with an inhibitor, 2-deoxy-2,3-dehydro-N-acetyl neuraminic acid (DANA). Native and inhibitor complex crystals are isomorphous and belong to space group I...

953 S from one influenza season to the next, we have lost the use of our leading antiviral influenza drug because of resistance. This winter, the circulating strain of seasonal influenza A virus (H1N1) is resistant to the neuraminidase inhibitor osel tamivir. Moreover, rather than emerging under selective pressure of drug use, as many antibiotic-resistant bacteria do and as has been the concern...

Antibody responses to influenza virus hemagglutinin provide protection against infection and are well studied. Less is known about the human antibody responses to the second surface glycoprotein, neuraminidase. Here, we assessed human antibody reactivity to a panel of N1, N2, and influenza B virus neuraminidases in different age groups, including children, adults, and the elderly. Using enzyme-...