OBJECTIVES Pandemic H1N1/09 viruses with the neuraminidase H274Y mutation have emerged in untreated patients or following oseltamivir therapy or prophylaxis. There have been no reports yet of zanamivir-resistant H1N1/09 viruses in previously healthy patients. We wanted to determine whether we could select for neuraminidase mutations conferring high-level resistance to zanamivir by in vitro pass...

Neuraminidases (sialidases) have an essential role in the removal of terminal sialic acid residues from sialoglycoconjugates and are distributed widely in nature. The human lysosomal enzyme occurs in complex with beta-galactosidase and protective protein/cathepsin A (PPCA), and is deficient in two genetic disorders: sialidosis, caused by a structural defect in the neuraminidase gene, and galact...

Non-entrapped and liposome-entrapped Clostridium perfringens neuraminidase (0.5-0.6 unit) was injected into rats and its fate as well as its effect on plasma and erythrocyte N-acetylneuraminic acid was investigated. The following observations were made. (1) Although removal of both non-entrapped and liposome-entrapped neuraminidase from the circulation was completed within 5h after injection, t...

Oseltamivir-resistant H1N1 influenza viruses carrying the H275Y neuraminidase mutation predominated worldwide during the 2007-2009 seasons. Although several neuraminidase substitutions were found to be necessary to counteract the adverse effects of H275Y, the order and impact of evolutionary events involved remain elusive. Here we reconstruct H1N1 neuraminidase phylogeny during 1999-2009, estim...

An anthrapyrazole derivative STK663786 has been identified as a selective ligand of the socalled 430-cavity influenza virus neuraminidase at virtual screening library low-molecularweight compounds. It is able to form favorable contacts with hydrophobic residues well cationπ interaction and hydrogen bonds polar Arg371 residue. The experimentally determined EC₅₀ values have found be 19 30 µM for ...

A genomic library of Actinomyces viscosus T14V DNA in lambda gt11 was screened for expression of neuraminidase activities. Four recombinant clones were detected that gave blue fluorescence upon incubation with a fluorogenic substrate, 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid. Of these, two were identical, and all of the neuraminidase-positive clones shared a common 3.4-kbp DNA ...

influenza a viruses possesses two virion surface glycoproteins including haemagglutinin (ha) and neuraminidase (na). the na plays an important role in viral replication and promotes virus release from infected cells and facilitates virus spread throughout the body. to find out any genomic changes that might be occurred on na gene of avian influenza circulating viruses, we have genetically analy...

Arthrobacter sialophilus neuraminidase catalyzes the hydrolysis of N-acetylneuraminyl-alpha-oxygen, nitrogen, and azido glycosides. The most effective of those substrates examined was N-acetylneuraminyl-alpha-4-methylumbelliferylglycoside (AcNeu-alpha-4-MU; Km app, 0.0193 mM; kcat, 136.4 sec-1). The products resulting from the enzymic hydrolysis of N-acetylneuraminyl-alpha-azido-glycoside were ...

Received January 14, 2014 It is critical to seek potential alternative treatments for H1N1 infections by inhibiting neuraminidase-1 enzyme. One of the viable options for inhibiting the activity of neuraminidase-1 is peptide drug design. In order to increase peptide stability, cyclization is necessary to prevent its digestion by protease enzyme. Cyclization of peptide ligands by formation of dis...

Lysosomal neuraminidase (sialidase) occurs in a high molecular weight complex with the glycosidase beta-galactosidase and the serine carboxypeptidase protective protein/cathepsin A (PPCA). Association of the enzyme with PPCA is crucial for its correct targeting and lysosomal activation. In man two genetically distinct storage disorders are associated with either a primary or a secondary deficie...