human ace 2 fc chimera protein  (R&D Systems)

Journal: International Journal of Molecular Sciences

Article Title: Molecular Interactions of Tannic Acid with Proteins Associated with SARS-CoV-2 Infectivity

doi: 10.3390/ijms23052643

Figure Lengend Snippet: Inhibitory effects of different polyphenols on the interaction between SARS-CoV-2 spike protein receptor binding domain (RBD (N501Y)) and human angiotensin-converting enzyme 2 (ACE2). ( A ) 10 µM of pelargonidin-3-O-glucoside (Pel-3-O-G), malvidin-3-O-glucoside (Mal-3-O-G), cyanidin-3-O-glucoside (Cya-3-O-G), peonidin, tannic acid (TA), 1,3,6-tri-O-galloyl-β-D-glucose (TGG), and corilagin were tested to evaluate their ability to inhibit the binding of immobilized spike protein (0.5 µg/mL) to human, biotin-labeled ACE2 (0.25 µg/mL) by using an enzyme-linked immunosorbent assay (ELISA). Dose effect inhibition of 0.1, 1, and 5 µM ( B ) TA, ( C ) TGG, and ( D ) corilagin. The absorbance of ACE2 (0.25 µg/mL) at 450 nm was set to 100%. Results are expressed as mean ± SD (n = 3). Statistical analysis was performed using one-way ANOVA followed by the Tukey post hoc test with * p < 0.05, ** p < 0.01, *** p < 0.001 compared to ACE2 (0.25 µg/mL).

Article Snippet: Biotinylated recombinant human ACE2 with purity >95% and camostat mesylate compound were both purchased from R&D Systems (Minneapolis, MN, USA).

Techniques: Binding Assay, Labeling, Enzyme-linked Immunosorbent Assay, Inhibition

Journal: Clinical Immunology (Orlando, Fla.)

Article Title: Seroprevalence and SARS-CoV-2 cross-reactivity of endemic coronavirus OC43 and 229E antibodies in Finnish children and adults

doi: 10.1016/j.clim.2021.108782

Figure Lengend Snippet: SARS-CoV-2 neutralization potency of the pre-pandemic hCoV antibodies. Individual sera ( n = 10) positive (grey columns) or negative (white columns) for SARS-CoV-2 receptor-binding domain (RBD) and/or spike-specific antibodies were used to block spike (a) or RBD (b) proteins binding to immobilized human angiotensin-converting enzyme 2 (ACE-2) in a surrogate neutralization assay. RBD-specific monoclonal antibody (mAb) was used as positive blocking control (black columns). The columns represent the binding inhibition percent (%) for each sample was calculated as 100% - (optical density [OD] of ACE-2 binding in the presence of serum/OD of ACE-2 maximum binding × 100%). The numerical values above/inside columns illustrate the OD-values obtained from spike (a) or RBD (b) -specific IgG ELISAs.

Article Snippet: Ninety-six well plates (Corning) were coated overnight with human ACE-2 (hACE-2, aa18–740) Fc chimera recombinant protein (1 μg/ml in PBS, Invitrogen) and the plates were blocked with 5% milk in PBS for one hour at RT.

Techniques: Neutralization, Binding Assay, Blocking Assay, Inhibition