Date Published: July , 2009
Publisher: A.I. Gordeyev
Author(s): Y.A. Shtyrya, L.V. Mochalova, N.V. Bovin.
The structure of the influenza virus neuraminidases, the spatial organization of their active site, the mechanism of carbohydrate chains desialylation by neuraminidase, and its role in the influenza virus function at different stages of the viral infectious cycle are considered in this review. Data on the neuraminidase substrate specificity and different approaches in studying the activity of this enzyme are summarized. In addition, data on neuraminidase inhibitors (as antivirals) are provided, along with considerations on the mechanisms of resistance of modern influenza viruses to those antivirals.
The NA’s reaction mechanism (Scheme 1) was proposed based on the results of structural studies of the crystallized protein .
The structure of the neuraminidase active site is strictly conservative not only between subtypes, but also between the types of the enzyme, which points to the importance of all its components and the evolutionary stabilized functioning of this system. This observation has allowed to design an NA inhibitor for the influenza virus which mimics the transition state of the hydrolysis reaction, and Neu5Ac2en (Fig.2а), 4-guanidino-Neu5Ac2en, which is now widely used under the trade name zanamivir  (Fig. 2b).