Chemical Insight Into the Influenza A Virus Hemagglutinin Binding to the Sialoside Revealed by the Fragment Molecular Orbital Method

The present mini-review aims first at an introduction to two thermodynamic essentials of the binding between the influenza A virus hemagglutinin (HA) and the cell surface receptor sialoside, (1) the equilibrium 1:1 binding of the HA with the sialoside, (2) the polyvalent effect of the HA binding to the polyvalent sialoside. Second, the review introduces the fragment molecular orbital (FMO) studies of the HA-sialoside (1:1) complexes. The recent FMO method with the polarizable continuum model as one of the residue-based energy analysis method has revealed the role of key amino acid residue on the selective HA subtype H3 binding to the sialosides.