Basic Information
Remarks
Chemical Identifiers
Basic Properties
Lipinski RO5
Hydrophobic Tag Properties
Mechanism of Action
POI (Protein of Interest)
Amino Acid Sequence
3D Structure (/structures/AF-0000000211971556-model_v1.cif)
Function
Catalyzes the removal of terminal sialic acid residues from viral and cellular glycoconjugates. Cleaves off the terminal sialic acids on the glycosylated HA during virus budding to facilitate virus release. Additionally helps virus spread through the circulation by further removing sialic acids from the cell surface. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell. Otherwise, infection would be limited to one round of replication. Described as a receptor-destroying enzyme because it cleaves a terminal sialic acid from the cellular receptors. May facilitate viral invasion of the upper airways by cleaving the sialic acid moieties on the mucin of the airway epithelial cells. Likely to plays a role in the budding process through its association with lipid rafts during intracellular transport. May additionally display a raft-association independent effect on budding. Plays a role in the determination of host range restriction on replication and virulence. Sialidase activity in late endosome/lysosome traffic seems to enhance virus replication.
Degradation Pathway
Mechanism
The ubiquitin-proteasome pathway (UPP) constitutes the principal pathway for protein degradation in eukaryotic cells, mediating the breakdown of target proteins through ubiquitin tagging and subsequent proteasomal degradation. In an ATP-dependent manner, the ubiquitin-activating enzyme (E1) activates ubiquitin (Ub) and conjugates it to a ubiquitin-conjugating enzyme (E2). E3 ligase subsequently catalyzes the transfer of Ub to the target protein, leading to the formation of a polyubiquitin chain that completes the ubiquitination mark. The 19S regulatory particle of the 26S proteasome recognizes this ubiquitination signal and, after deubiquitination, mediates the ATP-dependent delivery of the substrate into the 20S proteasome for degradation.
Description
To elucidate the mechanism of neuraminidase degradation in HEK293T cells, rescue assays were performed. Pretreatment with the proteasome inhibitor MG-132 (5 μM) effectively blocked compound 7j-induced neuraminidase degradation (Figure 3E), indicating the essential role of the proteasome pathway. In contrast, pretreatment with the lysosomal inhibitor chloroquine (100 μM) had no effect (Figure 3E), suggesting that lysosome pathways are not involved. Consistent with a degradation-dependent mechanism, proteasome inhibition reduced the incremental antiviral activity of 7j over ZMV (Figure S8A-B), and Western blot analysis under the same conditions confirmed that MG-132 restored NA protein levels (Figure S8C). Given the known role of Hsp70 in mediating proteasomal degradation of misfolded proteins, coimmunoprecipitation (Co-IP) pulldown experiments were further performed. The results revealed that treatment with compound 7j for 24 h enhanced interactions between neuraminidase and both Hsp70 and ubiquitin (Figure 3F), suggesting that compound 7j promotes the recruitment of these factors to facilitate neuraminidase degradation.
Activity Data
Description
Western blot analysis demonstrates that compound 7j potently induced the degradation of both wild-type neuraminidase and mutant neuraminidase variants in a dose- and time-dependent manner (Figure 3A-B). The cellular DC50 for NA degradation by 7j was determined to be 636.6 nM (Figure S7).
Description
Western blot analysis demonstrates that compound 7j potently induced the degradation of both wild-type neuraminidase and mutant neuraminidase variants in a dose- and time-dependent manner (Figure 3A-B). A maximum degradation (∼ 95%) was achieved after 24 h of treatment with 5 μM compound 7j..
Description
Dose-dependent assays confirmed the broad-spectrum antiviral activity of compound 7j, which showed the EC50 values of 11.13 nM (A/WSN/1933), 12.55 nM (A/Puerto Rico/8/34), and 12.09 nM (A/Darwin/9/2021), approximately 2-fold lower than those of oseltamivir (OSV) and ZMV.
Description
Dose-dependent assays confirmed the broad-spectrum antiviral activity of compound 7j, which showed the EC50 values of 11.13 nM (A/WSN/1933), 12.55 nM (A/Puerto Rico/8/34), and 12.09 nM (A/Darwin/9/2021), approximately 2-fold lower than those of oseltamivir (OSV) and ZMV.
Description
Dose-dependent assays confirmed the broad-spectrum antiviral activity of compound 7j, which showed the EC50 values of 11.13 nM (A/WSN/1933), 12.55 nM (A/Puerto Rico/8/34), and 12.09 nM (A/Darwin/9/2021), approximately 2-fold lower than those of oseltamivir (OSV) and ZMV.
Description
Moreover, compound 7j displayed minimal cytotoxicity, with a CC50 over 200 μM, compared to 55.7 μM for Aman (Figure S1).
PK (Pharmacokinetics)
| Route | Dose | T1/2 | Tmax | Cmax | AUC | MRT | CL | F | Vd | Vz |
|---|---|---|---|---|---|---|---|---|---|---|
| I.V. | 2 μmol/kg | 5.72±0.45 h | (0-24h)282678.35±49527.05 h*nM (0-∞)303008.51±55291.35 h*nM | (0-24h)6.08±0.09 h (0-∞)8.11±0.29 h | 0.01±0.00 L/h/kg | 0.06±0.01 L/kg | ||||
| I.N. | 2 μmol/kg | 10.31±1.83 h | 2266.57±112.03 ng/mL | (0-24h)32428.21±1006.31 h*nM (0-∞)35982.79±989.77 h*nM | 11.87 % | |||||
| I.G. | 2 μmol/kg | 12.37±1.52 h | 896.92±67.48 ng/mL | (0-24h )8930.24±465.26 h*nM (0-∞)9326.52±339.78 h*nM | 3.19 % |
Disease Information
| Disease | ICD-11 | Source |
|---|---|---|
| Congenital sialidosis type 2 | 5C56.21 | Gene-Disease Association |
| Juvenile sialidosis type 2 | 5C56.21 | Gene-Disease Association |
| Sialidosis type 1/2 | 5C56.21 | Gene-Disease Association |
| Glycoproteinosis | 5C56.2Z | Gene-Disease Association |
| Hydrops Fetalis, Nonimmune | KC41.1 | Gene-Disease Association |
| Gm1 Gangliosidosis | 5C56.00 | Gene-Disease Association |
| Acid Phosphatase Deficiency | 5C64.3 | Gene-Disease Association |