Pineapple Lectin AcmJRL Binds SARS-CoV-2 Spike Protein in a Carbohydrate-Dependent Fashion

The highly glycosylated spike protein of SARS-CoV-2 is essential for infection and constitutes a prime target for antiviral agents and vaccines. The pineapple-derived jacalin-related lectin AcmJRL is present in the medication bromelain in significant quantities and has previously been described to bind mannosides. Here, we performed a large ligand screening of AcmJRL by glycan array analysis, quantified the interaction with carbohydrates and validated high-mannose glycans as preferred ligands. Because the SARS-CoV-2 spike protein was previously reported to carry a high proportion of high-mannose N-glycans, we tested the binding of AcmJRL to the recombinantly produced extraviral domain of spike protein. We could demonstrate that AcmJRL binds the spike protein with a low-micromolar K-D in a carbohydrate-dependent fashion.

Automated summary

The highly glycosylated spike protein of SARS-CoV-2 is crucial for infection and is a target for antiviral agents and vaccines. A pineapple-derived lectin AcmJRL has been found to bind mannosides and is present in the medication bromelain. This study showed that AcmJRL binds to the spike protein of SARS-CoV-2 with a low-micromolar K-D in a carbohydrate-dependent manner.