Lectins Used For Coronavirus Research
Lectins from various sources have been shown to exhibit potent antiviral properties by inhibiting infection of clinically important viral pathogens. The antiviral activity of lectins is largely attributed to direct binding to viral envelope glycans and preventing entry of the virus into cells. Several lectins, particularly plant lectins with affinity toward mannose and N-acetylglucosamine (GlcNAc) sugar moieties, have been identified as potential therapeutic agents in the prevention of viral transmission in human immunodeficiency virus (HIV) and coronaviruses (SARS-CoV and MERS-CoV) .
Coronaviruses are enveloped single-stranded RNA viruses that contain at least four structural proteins: the membrane (M), envelope (E), spike (S) and nucleocapsid (N) protein. The heavily glycosylated S protein mediates virus–cell attachment and fusion. Mannose-binding lectins interfere with the coronavirus entry process by binding to the high-mannose type N-glycans of SARS-CoV via the S protein, preventing viral attachment to the host cell [2, 3].
N-glycans on the coronavirus S protein may result in activation of a downstream antiviral innate immune response. N-linked glycosylation plays a critical role in the specific interaction between the mannose-binding lectin and SARS-CoV S protein. This interaction can also negatively affect receptor binding of the coronavirus .
Vector Laboratories is an established manufacturer of many plant lectins that are described in the literature as valuable tools in ongoing research to elucidate their potential in suppression of viral activity. Below is a list of mannose-specific and mannose/glucose-specific lectins, available in unconjugated and conjugated formats.
- Galanthus nivalis
- Hippeastrum hybrid
- Narcissus pseudonarcissus
- Concanavalin A
- Lens culinaris
- Musa paradisiaca
- Pisum sativum
Based on prior studies on coronaviruses such as SARS-CoV and MERS-CoV, mannose-specific plant lectins can be used to investigate antiviral properties of the novel coronavirus SARS-CoV-2, the virus that causes COVID-19.
- Mitchell, C. et al. Antiviral Lectins: Selective Inhibitors of Viral Entry. Antiviral Res. 2017 Jun; 142: 37–54. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5414728/)
- Keyaerts, E. et al. Plant lectins are potent inhibitors of coronaviruses by interfering with two targets in the viral replication cycle. Antiviral Res. 2007 Sep;75(3):179-87. (https://www.ncbi.nlm.nih.gov/pubmed/17428553)
- Ritchie, G., et al. Identification of N-linked carbohydrates from severe acute respiratory syndrome (SARS) spike glycoprotein. Virology. 2010 Apr 10;399(2):257-69.
- Fung, S. and Liu, DX. Post-translational modifications of coronavirus proteins: roles and function. Future Virol. (2018) 13(6), 405–430. (https://www.futuremedicine.com/doi/full/10.2217/fvl-2018-0008)