Abstract
The COVID-19 pandemic has led to a global crisis with devastating effects on public healthcare and the economy. Sensitive detection of SARS-CoV-2 is the key to diagnose and control its spread. The spike (S) protein is an abundant viral transmembrane protein and a suitable target protein for the selective recognition of SARS-CoV-2. Here, we report that with bovine serum albumin prescreening, a specific phage peptide targeting SARS-CoV-2 S1 protein was biopanned with the pIII phage display library. The identified phage #2 expressing the peptide (amino acid sequence: NFWISPKLAFAL) shows high affinity to the target with a dissociation constant of 3.45 ± 0.58 nM. Furthermore, the identified peptide shows good specificity with a binding site at the N-terminal domain of the S1 subunit through a hydrogen bond network and hydrophobic interaction, supported by molecular docking. Then, a sandwiched phage-based enzyme-linked chemiluminescence immunoassay (ELCLIA) was established by using phage #2 as a bifunctional probe capable of SARS-CoV-2 S1 antigen recognition and signal amplification. After optimizing the conditions, the proposed phage ELCLIA exhibited good sensitivity, and as low as 78 pg/mL SARS-CoV-2 S1 could be detected. This method can be applied to detect as low as 60 transducing units (TU)/mL SARS-CoV-2 pseudovirus in 50% saliva. Therefore, specific phage peptides have good prospects as powerful biological recognition probes for immunoassay detection and biomedical applications.
【초록키워드】 SARS-CoV-2, Saliva, COVID-19 pandemic, Economy, peptide, molecular docking, binding site, Spread, Protein, immunoassay, amplification, sensitivity, specificity, pseudovirus, chemiluminescence immunoassay, healthcare, albumin, peptides, bovine, target, SARS-CoV-2 pseudovirus, serum albumin, sensitive, diagnose, Dissociation constant, N-terminal domain, Amino acid, Interaction, S1 subunit, amino acid sequence, hydrogen, bovine serum albumin, high affinity, hydrophobic, selective, target protein, transmembrane protein, phage, SARS-CoV-2 S1, probe, SARS-CoV-2 S1 protein, Effect, hydrogen bond network, antigen recognition, the S1 subunit, detect, exhibited, supported, expressing, conditions, transducing, 【제목키워드】 spike, sensitive, the SARS-CoV-2,