Hemagglutinins inhibition

Functional assays that assess neutralizing Ab, hemagglutinin inhibition, cytotoxic T cell, and other effector functions... 

Viruses don t have a reproductive system of their own and need to take over healthy cells by puncturing them with tiny spikes called hemagglutinin so that they can use the cells reproductive mechanism to make more viruses. These viral spikes are coated with an enzyme called neuraminidase, which helps to break down cellular walls. Flavonoids that occur in elderberries inhibit viral action and thereby improve immune response. It is thought that the flavoniods may also inhibit the action of neuraminidase. 

Bodian, D.L., Yamasaki, R.B., Buswell, R.L., Stearns, J.F., and White, J.M. Inhibition of the fusion-inducing conformational change of influenza hemagglutinin by benzoquinones and hydroquinones. Biochemistry. 1993, 32, 2967-2978. 

Their mechanism of action involves inhibition of the viral M2 protein, an integral membrane protein that acts as a H channel Blockade of the M2 protein prevents the acid-mediated dissociation of the ribonucleoprotein complex that occurs early in replication. In certain strains, the pH changes that result from M2 inhibition alter the conformation of hemagglutinin, hence inhibit viral assembly. 

Zanamivir (Relenza) is a neuraminidase inhibitor with activity against influenza A and B strains. Like oseltamivir, zanamivir is a reversible competitive antagonist of viral neuraminidase. It inhibits the release of progeny virus, causes viral aggregation at the cell surface, and impairs viral movement through respiratory secretions. Resistant variants with hemagglutinin and/or neuraminidase mutations have been produced in vivo however, clinical resistance to zanamivir is quite rare at present. 

It has been reported that the antigenic shifts are manifested in hemagglutinin and neuraminidase, two glycoproteins found on the surface of the influenza virion. It is suggested that the hemagglutinin binds the virus to t he target cell and when the hemagglutinin function is inhibited... 

Lectins (hemagglutinins) in raw soybeans can inhibit growth and cause death in animals. They are proteins that bind to carbohydrate-containing molecules and cause blood clotting. Fortunately lectins are degraded rapidly by heating. Soybeans also contain growth inhibitors that are not easily deactivated by heat treatment. 

Interestingly, Matsumoto and Osawa196 reported that p-nitrophenyl (and phenyl) 2-acetamido-2-deoxy-/3-D-glucopyranoside, at a concentration of 10 mg/ml, did not inhibit the agglutination reaction between the potato lectin and human erythrocytes, whereas both p-nitrophenyl 2-acetamido-2,6-dideoxy-/3-D-gIucopyranoside and phenyl 2-acet-amido-3-0-(D-l-carboxyethyl)-2-deoxy-j3-D-glucopyranoside, at a level of 5 mg/ml, completely inhibited the hemagglutinin reaction. The... 

Inhibition of Helix pomatia Hemagglutinin-Blood-group A Substance Precipitation by Various Saccharides582... 

Sugar Inhibition of R. communis Hemagglutinin-Alfalfa Galactomannan Precipitation124... 

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