Cell adhesion as a novel approach to determining the cellular binding motif on the severe acute respiratory syndrome coronavirus spike protein

Abstract

Emerging life threatening pathogens such as severe acute aspiratory syndrome-coronavirus (SARS-CoV), avian-origin influenzas H7N9, and the Middle East respiratory syndrome coronavirus (MERS-CoV) have caused a high case-fatality rate and psychological effects on society and the economy. Therefore, a simple, rapid, and safe method to investigate a therapeutic approach against these pathogens is required. In this study, a simple, quick, and safe cell adhesion inhibition assay was developed to determine the potential cellular binding site on the SARS-CoV spike protein. Various synthetic peptides covering the potential binding site helped to minimize further the binding motif to 10-25 residues. Following analyses, 2 peptides spanning the 436-445 and 437-461 amino acids of the spike protein were identified as peptide inhibitor or peptide vaccine candidates against SARS-CoV.

Suppressed humoral immunity is associated with dengue nonstructural protein NS1-elicited anti-death receptor antibody fractions in mice

“…All serum samples of protein immunized rabbits were collected 7-10 days after the 5 th immunization cycle of aforementioned recombinant proteins. To enhance the immunization efficiency in rabbit and mouse experiments, the recombinant proteins (250 μg/rabbit; 50 μg/mouse) were emulsified with complete Freund's adjuvant (Sigma-Aldrich, St. Louis, MO) in the first immunization; in the later boosting cycles, incomplete Freund's adjuvant (Sigma-Aldrich) was used 1:1 (v/v) mixed with recombinant proteins, 100 μg/rabbit; 25 μg/mouse) as www.nature.com/scientificreports www.nature.com/scientificreports/ described 30,73,74 . The induction of IgG titers against specific antigens was confirmed using enzyme-linked immunosorbent assay (ELISA).…”

Multifunctional biophotonic nanostructures inspired by the longtail glasswing butterfly for medical devices

“…The HeLa cell line was chosen as a representative eukaryote for its proven robustness, aggressive growth rate, and adherent nature that prompts its frequent usage in adhesion and cytotoxicity assays 41,42 . After 72 hours, the adherent cell density on the flat Si 3 N 4 was eight times greater than that on the nanostructured Si 3 N 4 surface (Fig.…”

Suppressive effect of dengue virus envelope protein domain III on megakaryopoiesis

“…The expression plasmid pGEX-2KS 28,29 was transformed into the E. coli strain BL21 (DE3) and induced to express the protein, which was purified according to the protocol of our previous study. 30 Endotoxin contamination was verified through the Limulus Amoebocyte Lysate assay (Lonza), according to the manufacturer's instructions as described previously. 28,31 Antibodies generation and purification Antibodies against DENV-EIII were generated and purified following the procedure detailed in a previous study with some modifications.…”

“…28,31 Antibodies generation and purification Antibodies against DENV-EIII were generated and purified following the procedure detailed in a previous study with some modifications. 30 Protein G Sepharose 4 Fast Flow (GE Healthcare) was used to purify immunoglobulin G (IgG) from the serum of DENV-EIII immunized rabbits according to the manufactory's instructions. Eluted IgG was dialyzed using normal saline (0.9% NaCl) and concentrated using polyethylene glycol 20000.…”