Blocking Effect of Demethylzeylasteral on the Interaction between Human ACE2 Protein and SARS-CoV-2 RBD Protein Discovered Using SPR Technology

Abstract

The novel coronavirus disease (2019-nCoV) has been affecting global health since the end of 2019, and there is no sign that the epidemic is abating. Targeting the interaction between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and the human angiotensin-converting enzyme 2 (ACE2) receptor is a promising therapeutic strategy. In this study, surface plasmon resonance (SPR) was used as the primary method to screen a library of 960 compounds. A compound 02B05 (demethylzeylasteral, CAS number: 107316-88-1) that had high affinities for S-RBD and ACE2 was discovered, and binding affinities (KD, μM) of 02B05-ACE2 and 02B05-S-RBD were 1.736 and 1.039 μM, respectively. The results of a competition experiment showed that 02B05 could effectively block the binding of S-RBD to ACE2 protein. Furthermore, pseudovirus infection assay revealed that 02B05 could inhibit entry of SARS-CoV-2 pseudovirus into 293T cells to a certain extent at nontoxic concentration. The compoundobtained in this study serve as references for the design of drugs which have potential in the treatment of COVID-19 and can thus accelerate the process of developing effective drugs to treat SARS-CoV-2 infections.

Identification of SARS-CoV-2 Receptor Binding Inhibitors by In Vitro Screening of Drug Libraries

“…Inhibiting the RBD-ACE2 interaction, thereby preventing viral attachment to target cells, is used as an approach to develop vaccines and therapeutics. The latter include antibodies, aptamers, peptides, and specific small-molecule inhibitors (SMIs) [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. One effective and rapid strategy for discovering inhibitors is by screening compound libraries, as was recently applied to find new therapeutics for COVID-19.…”

Screening S protein – ACE2 blockers from natural products: Strategies and advances in the discovery of potential inhibitors of COVID-19

“…SPR technology can be used to rapidly screen lead compounds by detecting the K D value of the interaction between the target protein and small molecules. Zhu [ 85 ]captured the ACE2-His protein as ligand, dissolved S-RBD-mFc in buffer solution as analyte to establish an SPR screening model of S-RBD and ACE2. When the compounds flowed through the chip surface fixed with ACE2 or S-RBD, the K D value was determined to screen the compounds that could bind to ACE2 or S-RBD.…”

“…The results showed that glycyrrhizic acid (16) was an effective anti-coronavirus active ingredient in vitro with low toxicity, which might be a potential candidate drug for anti-coronavirus. Zhu [ 85 ] established the SPR screening model of S-RBD and ACE2, the results showed that demethylzeylasteral (19) could bind to S-RBD and block the binding of S-RBD and ACE2. In addition, there are other triterpenoids such as ursolic acid (18), Maslinic Acid (20), obacunone (21), atractylenolide III (23), and astragaloside IV (24), which were confirmed that they could bind to ACE2 or S protein as S-protein-ACE2 blockers through a variety of VS methods, and the chemical structure is shown in Fig.…”

Structure-Based Virtual Screening and Identification of Potential Inhibitors of SARS-CoV-2 S-RBD and ACE2 Interaction

“…Recently, virtual screening and high throughput screening studies targeting SARS-CoV-2 S-RBD/ACE2 interaction have discovered several small molecule inhibitors ( Figure 1B ) ( Carino et al, 2020 ; Fu et al, 2020 ; Hanson et al, 2020 ; Yu et al, 2020 ; Zhu et al, 2021 ). Nevertheless, the antiviral activities of some compounds, such as corilagin, glycoursodeoxycholic acid, and glycyrrhizic acid, are not clear ( Carino et al, 2020 ; Hanson et al, 2020 ; Yu et al, 2020 ).…”