Development of flexible electrochemical impedance spectroscopy-based biosensing platform for rapid screening of SARS-CoV-2 inhibitors

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the cells through the binding of its spike protein (S-protein) to the cell surface-expressing angiotensin-converting enzyme 2 (ACE2). Thus, inhibition of S-protein-ACE2 binding may impede SARS-CoV-2 cell entry and attenuate the progression of Coronavirus disease 2019 (COVID-19). In this study, an electrochemical impedance spectroscopy-based biosensing platform consisting of a recombinant ACE2-coated palladium nano-thin-film electrode as the core sensing element was fabricated for the screening of potential inhibitors against S-protein-ACE2 binding. The platform could detect interference of small analytes against S-protein-ACE2 binding at low analyte concentration and small volume (0.1 μg/mL and ~1 μL, estimated total analyte consumption < 4 pg) within 21 min. Thus, a few potential inhibitors of S-protein-ACE2 binding were identified. This includes (2S,3aS,6aS)-1-((S)–N-((S)-1-Carboxy-3-phenylpropyl)alanyl)tetrahydrocyclopenta[b] pyrrole-2-carboxylic acid (ramiprilat) and (2S,3aS,7aS)-1-[(2S)-2-[[(2S)-1-Carboxybutyl]amino]propanoyl]-2,3,3a,4,5,6,7,7a-octahydroindole-2-carboxylic acid (perindoprilat) that reduced the binding affinity of S-protein to ACE2 by 72% and 67%; and SARS-CoV-2 in vitro infectivity to the ACE2-expressing human oral cavity squamous carcinoma cells (OEC-M1) by 36.4 and 20.1%, respectively, compared to the PBS control. These findings demonstrated the usefulness of the developed biosensing platform for the rapid screening of modulators for S-protein-ACE2 binding.

Angiotensin-Converting Enzyme 2 (ACE2) As a Novel Biorecognition Element in A Cell-Based Biosensor for the Ultra-Rapid, Ultra-Sensitive Detection of the SARS-CoV-2 S1 Spike Protein Antigen

“…They determined that the S1-RBD has a strong intrinsic affinity for ACE2 (~120 nM), possibly extended to the whole-virus level. More recently, Kiew et al [47] applied an electrochemical impedance spectroscopy (EIS)-based biosensing platform having a recombinant ACE2-coated palladium electrode as the core sensing element for screening potential pharmacological inhibitors against S1-ACE2 interaction. The panel of tested compounds comprised FDA-approved peptide analogs computationally predicted to promote hydrogen bonding interactions with ACE2, including ramipril, perindopril and cilazapril.…”

Protein-Protein Interactions: Insight from Molecular Dynamics Simulations and Nanoparticle Tracking Analysis

“…Apart from MD simulations and NTA, binding activity was also validated by the EIS method. EIS offers a highly sensitive and selective technique for most bio-sensor studies involving large biomolecules, such as proteins [ 45 , 46 , 47 ]. The detection principle works on measuring changes of electrochemical signals such as charge transfer [ 48 , 49 ], capacitance [ 50 ] or impedance [ 51 , 52 ].…”

Electrochemical sensors for the detection of SARS-CoV-2 virus

“…An entirely new electrochemical impedance spectroscopy-based sensor using angiotensin-converting enzyme 2 (ACE2)-coated palladium nano-thin film (Pd-NTF) was developed by Kiew et al, [78] to detect potential inhibitors against SARS-CoV-2 S protein-ACE2 binding. In this, EIS-based biosensor ACE2-Pd-NTF electrode was the core sensing element to measure the changes due to the binding of SARS-CoV-2 S protein to ACE2 upon exposing to modulating molecules.…”