Sialidases data from

Fig. 5 Key interactions of 4-deoxy-4-guanidino-Neu5Ac2en (zanamivir) 12 with the active site of influenza A virus sialidase [Figure generated from crystal strucmre data (PDB - Innc) using LIGPLOT (Wallace et al. 1995)]. To the right is shown zanamivir 12 in the same orientation...

Fig. 5. The important interactions of Zanamivir (1) with the active site of influenza virus A sialidase.70 This figure was generated from crystal structure data (PDB-1NNC) using LIGPLOT.63...

A sialidase specific for FSH has not yet been demonstrated in human urine, although data derived from recovery experiments indicate that... 

Data obtained from the study of sialidases in Danio rerio suggest that other unexpected results may arise from the characterization of members of this gene family in other vertebrates, such as amphibians, reptiles, and avian species. 

Recent studies have suggested that certain plasma membrane-bound siali-dases are linked to the membranes via a GPI anchor, as observed with the sialidase from T. cruzi (Rosenberg et al., 1991). Phosphatidylinositol-specific phospholipase C (PIPLC) released sialidase activity (28% of total) from purified synaptosomal membranes of pig brain, but not from lysosomal membranes (Chiarini et al., 1990). The presence of GPI-anchored sialidase was also shown in human erythrocyte membranes (Chiarini et al., 1993). On the other hand, the sialidase activity in rat brain myelin could not be solubilized with PIPLC despite a concomitant release of alkaline phosphatase activity (about 40% of total), suggesting a different mode of association of the enzyme with the membranes (Saito and Yu, unpublished data). 

Figure 2. The structure of the sialidase of influenza A virus. The model has been derived from the crystallographic data obtained on A/tem/Australia/G70C/75 sialadase (Baker et al., 1987). View of the monomer is down the fourfold symmetry axis. The catalytic site (white) is indicated. The receptor binding site (black) observed on some sialidase molecules is also shown. For details see text.

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