background and aims: influenza (flu) is a respiratory infection in mammals and birds. it is caused by an rna virus in the family orthomyxoviridae. the virus is divided into three main types. influenza virus type a is found in a wide variety of bird and mammal species and can undergo major shifts in immunological properties. hemagglutinin (ha) is an important influenza virus surface antigen that...

background and aims: hemagglutinin (ha) protein of avian influenza (ai) plays an essential role in the virus pathogenicity. ai h9n2 subtype causes significant economic loss in broiler and layer in poultry farms in iran. ai viruses have a great involvement in evolutionary changes at nucleotide and amino acid levels and vaccines could induce faster rates of such changes. up-dated understanding of...

objective: influenza virus a (h1n1) is an important subtype of the influenza respiratory viruses, which has important worldwide implications. hemagglutinin (ha), an important viral antigen, is responsible for binding to human cell receptors leading to an onset of the disease process. considering the critical role of viral attachment, this study focuses on the extraction and cloning of ha and it...

Five toxigenic strains of Clostridium botulinum types C and D were incubated at 37 degrees C for 7 days in 15 ml of the following media: LYG medium, cooked-meat medium, egg meat medium, and N-Z-amine medium. The supernatants of these cultures were tested for hemagglutinin production with 1% erythrocytes obtained from mice, guinea pigs, chickens, sheep, monkeys, and humans. Four toxigenic strain...

abstract background and aims: influenza a(h5n1) viruses  circulating in animals might evolve and acquire the ability to spread from  human to human and thus start a pandemic. hemagglutinin (ha) has been shown to play a major role in binding of influenza virus to its target cell and the main neutralizing antibody responses elicit against this region. recent studies have shown that glycosylation ...

background and aims: influenza a(h5n1) viruses  circulating in animals might evolve and acquire the ability to spread from  human to human and thus start a pandemic. hemagglutinin (ha) has been shown to play a major role in binding of influenza virus to its target cell and the main neutralizing antibody responses elicit against this region. recent studies have shown that glycosylation of ha is ...

Antigenic determinants of influenza virus hemagglutinin were expressed in Escherichia coli. DNA coding for presequences of hemagglutinin were removed and an ATG codon was placed before DNA coding for mature hemagglutinin. A number of expression plasmids were constructed in which various segments of this reconstructed hemagglutinin DNA were fused to DNA coding for bacterial beta-galactosidase. T...

Neuraminidase treatment of human peripheral blood lymphocytes uncovers cell surface receptors that bind purified A hemagglutinin from the snail Helix pomatia. No hemagglutinin was bound to untreated lymphocytes. Binding studies with (125)I-labeled hemagglutinin suggested that the number of receptors on neuraminidase-treated lymphocytes was approximately 1.10(6)/cell. The apparent association co...

Influenza hemagglutinin, the receptor-binding and membrane fusion protein of the virus, is a prototypic model for studies of biological membrane fusion in general. To elucidate the minimum number of hemagglutinin trimers needed for fusion, the kinetics of fusion induced by reconstituted vesicles of hemagglutinin was studied by using single-vesicle image analysis. The surface density of hemagglu...

Botulism is a disease involving intoxication with botulinum neurotoxins (BoNTs), toxic proteins produced by Clostridium botulinum and other clostridia. The 150 kDa neurotoxin is produced in conjunction with other proteins to form the botulinum progenitor toxin complex (PTC), alternating in size from 300 kDa to 500 kDa. These progenitor complexes can be classified into hemagglutinin positive or ...