The S protein forming the homotrimeric spikes of pathogenic beta-coronaviruses, such as MERS-CoV, SARS-CoV and SARS-CoV-2, is a highly glycosylated protein containing mainly N-glycans of the complex and high-mannose type, as well as O-glycans. Similarly, the host cell receptors DPP4 for MERS-CoV and ACE2 for SARS-CoV and SARS-CoV-2, also represent N- and O-glycosylated proteins. All these glycoproteins share common glycosylation patterns, suggesting that plant lectins with different carbohydrate-binding specificities could be used as carbohydrate-binding agents for the spikes and their receptors, to combat COVID19 pandemics. The binding of plant lectins to the spikes and their receptors could mask the non-glycosylated receptor binding domain of the virus and the corresponding region of the receptor, thus preventing a proper interaction of the spike proteins with their receptors. In this review, we analyze (1) the ability of plant lectins to interact with the N- and O-glycans present on the spike proteins and their receptors, (2) the in vitro and in vivo anti-COVID19 activity already reported for plant lectins and, (3) the possible ways for delivery of lectins to block the spikes and/or their receptors.
Keywords: Aleuria aurantia lectin (AAL); Beta-coronaviruses; COVID-19; Con A; Galanthus nivalis agglutinin (GNA); Lens culinaris lectin (LcA); MERS-CoV; Man-specific lectin; Morus nigra lectin (Morniga-G); Pisum sativum lectin (PsA); SARS-CoV; SARS-CoV-2; Sambucus nigra lectin (SNA-I)..
© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.