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    Sino Biological sars cov 2 2019 ncov spike s1 his recombinant protein hplc verified covid 19 spike s1 research
    <t>SARS</t> VHH-72 Cross-Reacts with <t>SARS-CoV-2</t> (A) An SPR sensorgram measuring the binding of SARS VHH-72 to the SARS-CoV-2 <t>RBD-SD1.</t> Binding curves are colored black, and fit of the data to a 1:1 binding model is colored red. (B) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the RBD as a pink molecular surface. Amino acids that vary between SARS-CoV-1 and SARS-CoV-2 are colored green.
    Sars Cov 2 2019 Ncov Spike S1 His Recombinant Protein Hplc Verified Covid 19 Spike S1 Research, supplied by Sino Biological, used in various techniques. Bioz Stars score: 99/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/result/sars cov 2 2019 ncov spike s1 his recombinant protein hplc verified covid 19 spike s1 research/product/Sino Biological
    Average 99 stars, based on 1 article reviews
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    98
    Sino Biological sars cov 2 2019 ncov spike rbd his recombinant protein covid 19 spike rbd research
    <t>SARS</t> VHH-72 Cross-Reacts with <t>SARS-CoV-2</t> (A) An SPR sensorgram measuring the binding of SARS VHH-72 to the SARS-CoV-2 <t>RBD-SD1.</t> Binding curves are colored black, and fit of the data to a 1:1 binding model is colored red. (B) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the RBD as a pink molecular surface. Amino acids that vary between SARS-CoV-1 and SARS-CoV-2 are colored green.
    Sars Cov 2 2019 Ncov Spike Rbd His Recombinant Protein Covid 19 Spike Rbd Research, supplied by Sino Biological, used in various techniques. Bioz Stars score: 98/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
    https://www.bioz.com/result/sars cov 2 2019 ncov spike rbd his recombinant protein covid 19 spike rbd research/product/Sino Biological
    Average 98 stars, based on 1 article reviews
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    86
    Sino Biological sars cov 2 2019 ncov nucleocapsid his recombinant protein covid 19 nucleocapsid research
    Detection and quantification of <t>SARS-CoV-2</t> RBD- and N- reactive antibodies in pre-pandemic samples. (A) Representative dilution curves of seven pre-pandemic samples with SARS-CoV-2 RBD-reactive antibodies (three subjects per graph). Open and solid symbols represent buffer only coat and SARS-CoV-2 RBD coat, respectively. Arbitrary Units (AU) were calculated as described in Methods and shown beneath the respective isotype graph for diluent only and SARS-CoV-2 RBD coat. AUs for SARS-CoV-2 RBD (B) and N (C) reactive IgM, IgG, and IgA in pre-pandemic samples. Open and solid symbols represent negative and positive results, respectively, as determined by Metric 1. Enumeration of the positive samples for each isotype in the pre-pandemic cohort is shown beneath each graph with percentages of total in parentheses. (D) Correlation between AUs for IgG reactive to SARS-CoV-2 RBD and N (n=32). Values were log-transformed to obtain a parametric distribution. Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test in (B, C) and Pearson’s correlation of normally distributed AU values for (D) .
    Sars Cov 2 2019 Ncov Nucleocapsid His Recombinant Protein Covid 19 Nucleocapsid Research, supplied by Sino Biological, used in various techniques. Bioz Stars score: 86/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
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    Average 86 stars, based on 1 article reviews
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    Image Search Results


    SARS VHH-72 Cross-Reacts with SARS-CoV-2 (A) An SPR sensorgram measuring the binding of SARS VHH-72 to the SARS-CoV-2 RBD-SD1. Binding curves are colored black, and fit of the data to a 1:1 binding model is colored red. (B) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the RBD as a pink molecular surface. Amino acids that vary between SARS-CoV-1 and SARS-CoV-2 are colored green.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: SARS VHH-72 Cross-Reacts with SARS-CoV-2 (A) An SPR sensorgram measuring the binding of SARS VHH-72 to the SARS-CoV-2 RBD-SD1. Binding curves are colored black, and fit of the data to a 1:1 binding model is colored red. (B) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the RBD as a pink molecular surface. Amino acids that vary between SARS-CoV-1 and SARS-CoV-2 are colored green.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: SPR Assay, Binding Assay

    Neutralizing Mechanisms of MERS VHH-55 and SARS VHH-72 (A) The MERS-CoV spike (PDB ID: 5W9H ) is shown as a transparent molecular surface, with each monomer colored either white, gray, or tan. Each monomer is bound by MERS VHH-55, shown as blue ribbons. The clash between MERS VHH-55 bound to the white monomer and the neighboring tan RBD is highlighted by the red ellipse. (B) The SARS-CoV-1 spike (PDB ID: 5X58 ) is shown as a transparent molecular surface, with each protomer colored either white, gray, or pink. Every monomer is bound by a copy of SARS VHH-72, shown as dark blue ribbons. The clashes between copies of SARS VHH-72 and the two neighboring spike monomers are highlighted by the red circle. (C) The SARS-CoV-2 spike (PDB ID: 6VXX ) is shown as a transparent molecular surface, with each protomer colored either white, gray, or green. Every monomer is bound by a copy of SARS VHH-72, shown as dark blue ribbons. The clashes between copies of SARS VHH-72 and the two neighboring spike monomers are highlighted by the red circle. The SARS-CoV-2 trimer appears smaller than SARS-CoV-1 S because of the absence of flexible NTD-distal loops, which could not be built during cryo-EM analysis. (D) CoV VHHs prevent MERS-CoV RBD, SARS-CoV-1 RBD, and SARS-CoV-2 RBD-SD1 from interacting with their receptors. The results of the BLI-based receptor-blocking experiment are shown. The legend lists the immobilized RBDs and the VHHs or receptors that correspond to each curve.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: Neutralizing Mechanisms of MERS VHH-55 and SARS VHH-72 (A) The MERS-CoV spike (PDB ID: 5W9H ) is shown as a transparent molecular surface, with each monomer colored either white, gray, or tan. Each monomer is bound by MERS VHH-55, shown as blue ribbons. The clash between MERS VHH-55 bound to the white monomer and the neighboring tan RBD is highlighted by the red ellipse. (B) The SARS-CoV-1 spike (PDB ID: 5X58 ) is shown as a transparent molecular surface, with each protomer colored either white, gray, or pink. Every monomer is bound by a copy of SARS VHH-72, shown as dark blue ribbons. The clashes between copies of SARS VHH-72 and the two neighboring spike monomers are highlighted by the red circle. (C) The SARS-CoV-2 spike (PDB ID: 6VXX ) is shown as a transparent molecular surface, with each protomer colored either white, gray, or green. Every monomer is bound by a copy of SARS VHH-72, shown as dark blue ribbons. The clashes between copies of SARS VHH-72 and the two neighboring spike monomers are highlighted by the red circle. The SARS-CoV-2 trimer appears smaller than SARS-CoV-1 S because of the absence of flexible NTD-distal loops, which could not be built during cryo-EM analysis. (D) CoV VHHs prevent MERS-CoV RBD, SARS-CoV-1 RBD, and SARS-CoV-2 RBD-SD1 from interacting with their receptors. The results of the BLI-based receptor-blocking experiment are shown. The legend lists the immobilized RBDs and the VHHs or receptors that correspond to each curve.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: Blocking Assay

    Engineering a Functional Bivalent VHH Construct, Related to Figure 6 (A) Flow cytometry measuring the binding of the bivalent SARS VHH-72 tail-to-head fusion (VHH-72-VHH-72) to SARS-CoV-1 or SARS-CoV-2 S expressed on the cell surface. VHH-23-VHH-23, a bivalent tail-to-head fusion of an irrelevant nanobody, was included as a negative control. (B) Binding of SARS-CoV-2 RBD-SD1 to Vero E6 cells is prevented by VHH-72-VHH-72 in a dose-dependent fashion. Binding of SARS-CoV-2 RBD-SD1 to Vero E6 cells was detected by flow cytometry in the presence of the indicated bivalent VHHs (n = 2 except VHH-72-VHH-72 and VHH-23-VHH-23 at 5 μg/mL, n = 5). (C) Binding of SARS-CoV-2 RBD-SD1 to Vero E6 cells is prevented by bivalent VHH-72-Fc fusion proteins in a dose-dependent fashion. Binding of SARS-CoV-2 RBD-SD1-Fc to Vero E6 cells was detected by flow cytometry in the presence of the indicated constructs and amounts (n = 2 except no RBD, n = 4). (D) Cell surface binding of SARS VHH-72 to SARS-CoV-1 S. 293T cells were transfected with a GFP expression plasmid together with a SARS-CoV-1 S expression plasmid. Binding of the indicated protein is expressed as the median fluorescent intensity (MFI), measured to detect the His-tagged MERS VHH-55 or SARS VHH-72 or the SARS VHH-72-Fc fusions, of the GFP positive cells divided by the MFI of the GFP negative cells. (E) Cell surface binding of SARS VHH-72 to SARS-CoV-2. MFI was calculated using the same equation as Figure S6 D.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: Engineering a Functional Bivalent VHH Construct, Related to Figure 6 (A) Flow cytometry measuring the binding of the bivalent SARS VHH-72 tail-to-head fusion (VHH-72-VHH-72) to SARS-CoV-1 or SARS-CoV-2 S expressed on the cell surface. VHH-23-VHH-23, a bivalent tail-to-head fusion of an irrelevant nanobody, was included as a negative control. (B) Binding of SARS-CoV-2 RBD-SD1 to Vero E6 cells is prevented by VHH-72-VHH-72 in a dose-dependent fashion. Binding of SARS-CoV-2 RBD-SD1 to Vero E6 cells was detected by flow cytometry in the presence of the indicated bivalent VHHs (n = 2 except VHH-72-VHH-72 and VHH-23-VHH-23 at 5 μg/mL, n = 5). (C) Binding of SARS-CoV-2 RBD-SD1 to Vero E6 cells is prevented by bivalent VHH-72-Fc fusion proteins in a dose-dependent fashion. Binding of SARS-CoV-2 RBD-SD1-Fc to Vero E6 cells was detected by flow cytometry in the presence of the indicated constructs and amounts (n = 2 except no RBD, n = 4). (D) Cell surface binding of SARS VHH-72 to SARS-CoV-1 S. 293T cells were transfected with a GFP expression plasmid together with a SARS-CoV-1 S expression plasmid. Binding of the indicated protein is expressed as the median fluorescent intensity (MFI), measured to detect the His-tagged MERS VHH-55 or SARS VHH-72 or the SARS VHH-72-Fc fusions, of the GFP positive cells divided by the MFI of the GFP negative cells. (E) Cell surface binding of SARS VHH-72 to SARS-CoV-2. MFI was calculated using the same equation as Figure S6 D.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: Functional Assay, Construct, Flow Cytometry, Binding Assay, Negative Control, Transfection, Expressing, Plasmid Preparation

    VHH-72-Fc Neutralizes SARS-CoV-2 S Pseudoviruses (A) BLI sensorgram measuring apparent binding affinity of VHH-72-Fc to immobilized SARS-CoV-2 RBD-Fc. Binding curves are colored black, buffer-only blanks are colored gray, and the fit of the data to a 1:1 binding curve is colored red. (B) Time course analysis of VHH-72-Fc expression in ExpiCHO cells. Cell culture supernatants of transiently transfected ExpiCHO cells were removed on days 3–7 after transfection (or until cell viability dropped below 75%), as indicated. Two control mAbs were included for comparison, along with the indicated amounts of purified GBP-Fc as a loading control. (C) SARS-CoV-2 S pseudotyped VSV neutralization assay. Monolayers of Vero E6 cells were infected with pseudoviruses that had been pre-incubated with the mixtures indicated by the legend. The VHH-72-Fc used in this assay was purified after expression in ExpiCHO cells (n = 4). VHH-23-Fc is an irrelevant control VHH-Fc (n = 3). NI, cells were not infected. Luciferase activity is reported in counts per second (c.p.s.) ± SEM.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: VHH-72-Fc Neutralizes SARS-CoV-2 S Pseudoviruses (A) BLI sensorgram measuring apparent binding affinity of VHH-72-Fc to immobilized SARS-CoV-2 RBD-Fc. Binding curves are colored black, buffer-only blanks are colored gray, and the fit of the data to a 1:1 binding curve is colored red. (B) Time course analysis of VHH-72-Fc expression in ExpiCHO cells. Cell culture supernatants of transiently transfected ExpiCHO cells were removed on days 3–7 after transfection (or until cell viability dropped below 75%), as indicated. Two control mAbs were included for comparison, along with the indicated amounts of purified GBP-Fc as a loading control. (C) SARS-CoV-2 S pseudotyped VSV neutralization assay. Monolayers of Vero E6 cells were infected with pseudoviruses that had been pre-incubated with the mixtures indicated by the legend. The VHH-72-Fc used in this assay was purified after expression in ExpiCHO cells (n = 4). VHH-23-Fc is an irrelevant control VHH-Fc (n = 3). NI, cells were not infected. Luciferase activity is reported in counts per second (c.p.s.) ± SEM.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: Binding Assay, Expressing, Cell Culture, Transfection, Purification, Neutralization, Infection, Incubation, Luciferase, Activity Assay

    SARS VHH-72 Binds to a Broadly Conserved Epitope on the SARS-CoV-1 RBD, Related to Figure 3 (A) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown, with colors corresponding to those of Figure S4 A. (B) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the RBD as a pink molecular surface. Amino acids that vary between SARS-CoV-1 and WIV1-CoV are colored teal. (C) SPR sensorgram measuring the binding of SARS VHH-72 to the WIV1-CoV RBD. Binding curves are colored black and the fit of the data to a 1:1 binding model is colored red.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: SARS VHH-72 Binds to a Broadly Conserved Epitope on the SARS-CoV-1 RBD, Related to Figure 3 (A) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown, with colors corresponding to those of Figure S4 A. (B) The crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the RBD as a pink molecular surface. Amino acids that vary between SARS-CoV-1 and WIV1-CoV are colored teal. (C) SPR sensorgram measuring the binding of SARS VHH-72 to the WIV1-CoV RBD. Binding curves are colored black and the fit of the data to a 1:1 binding model is colored red.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: SPR Assay, Binding Assay

    The Crystal Structure of SARS VHH-72 Bound to the SARS-CoV-1 RBD (A) SARS VHH-72 is shown as dark blue ribbons and the SARS-CoV-1 RBD is shown as a pink-colored molecular surface. The ACE2 binding interface on the SARS-CoV-1 RBD is colored red. (B) The structure of ACE2 bound to the SARS-CoV-1 RBD (PDB ID: 2AJF ) is aligned to the crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD. ACE2 is shown as a red, transparent molecular surface. (C) A simulated N -linked glycan containing an energy-minimized trimannosyl core (derived from PDB ID: 1HD4 ) is modeled as red sticks, coming from Asn322 in ACE2. ACE2 is shown as a red molecular surface, the SARS-CoV-1 RBD is shown as pink ribbons, and SARS VHH-72 is shown as a dark blue, transparent molecular surface. (D) A zoomed-in view of the panel from (A) is shown, with the SARS-CoV-1 RBD now displayed as pink-colored ribbons. Residues that form interactions are shown as sticks, with nitrogen atoms colored dark blue and oxygen atoms colored red. Hydrogen bonds and salt bridges between SARS VHH-72 and the SARS-CoV-1 RBD are shown as black dots. (E) The same view from (D) has been turned by 60° to show additional contacts. Residues that form interactions are shown as sticks, with nitrogen atoms colored dark blue and oxygen atoms colored red. Interactions between SARS VHH-72 and the SARS-CoV-1 RBD are shown as black dots.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: The Crystal Structure of SARS VHH-72 Bound to the SARS-CoV-1 RBD (A) SARS VHH-72 is shown as dark blue ribbons and the SARS-CoV-1 RBD is shown as a pink-colored molecular surface. The ACE2 binding interface on the SARS-CoV-1 RBD is colored red. (B) The structure of ACE2 bound to the SARS-CoV-1 RBD (PDB ID: 2AJF ) is aligned to the crystal structure of SARS VHH-72 bound to the SARS-CoV-1 RBD. ACE2 is shown as a red, transparent molecular surface. (C) A simulated N -linked glycan containing an energy-minimized trimannosyl core (derived from PDB ID: 1HD4 ) is modeled as red sticks, coming from Asn322 in ACE2. ACE2 is shown as a red molecular surface, the SARS-CoV-1 RBD is shown as pink ribbons, and SARS VHH-72 is shown as a dark blue, transparent molecular surface. (D) A zoomed-in view of the panel from (A) is shown, with the SARS-CoV-1 RBD now displayed as pink-colored ribbons. Residues that form interactions are shown as sticks, with nitrogen atoms colored dark blue and oxygen atoms colored red. Hydrogen bonds and salt bridges between SARS VHH-72 and the SARS-CoV-1 RBD are shown as black dots. (E) The same view from (D) has been turned by 60° to show additional contacts. Residues that form interactions are shown as sticks, with nitrogen atoms colored dark blue and oxygen atoms colored red. Interactions between SARS VHH-72 and the SARS-CoV-1 RBD are shown as black dots.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: Binding Assay, Derivative Assay

    Comparison of the CoV VHH Epitopes with Known RBD-Directed Antibodies, Related to Figures 2 and 3 (A) The structure of MERS VHH-55 bound to the MERS-CoV RBD is shown with MERS VHH-55 as blue ribbons and the MERS-CoV RBD as a white molecular surface. Epitopes from previously reported crystal structures of the MERS-CoV RBD bound by RBD-directed antibodies are shown as colored patches on the MERS-CoV RBD surface. The LCA60 epitope is shown in yellow, the MERS S4 epitope is shown in green, the overlapping C2/MCA1/m336 epitopes are shown in red and the overlapping JC57-14/D12/4C2/MERS-27 epitopes are shown in purple. (B) The structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the SARS-CoV-1 RBD as a white molecular surface. Epitopes from previously reported crystal structures of the SARS-CoV-1 RBD bound by RBD-directed antibodies are shown as colored patches on the SARS-CoV-1 RBD surface. The 80R epitope is shown in blue, the S230 epitope is shown in yellow, the CR3022 epitope is shown in purple and the overlapping m396/F26G19 epitopes are shown in red. (C) The SARS-CoV-1 RBD is shown as a white molecular surface, ACE2 is shown as a transparent red molecular surface, SARS VHH-72 is shown as dark blue ribbons and CR3022 Fab is shown as purple ribbons.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: Comparison of the CoV VHH Epitopes with Known RBD-Directed Antibodies, Related to Figures 2 and 3 (A) The structure of MERS VHH-55 bound to the MERS-CoV RBD is shown with MERS VHH-55 as blue ribbons and the MERS-CoV RBD as a white molecular surface. Epitopes from previously reported crystal structures of the MERS-CoV RBD bound by RBD-directed antibodies are shown as colored patches on the MERS-CoV RBD surface. The LCA60 epitope is shown in yellow, the MERS S4 epitope is shown in green, the overlapping C2/MCA1/m336 epitopes are shown in red and the overlapping JC57-14/D12/4C2/MERS-27 epitopes are shown in purple. (B) The structure of SARS VHH-72 bound to the SARS-CoV-1 RBD is shown with SARS VHH-72 as dark blue ribbons and the SARS-CoV-1 RBD as a white molecular surface. Epitopes from previously reported crystal structures of the SARS-CoV-1 RBD bound by RBD-directed antibodies are shown as colored patches on the SARS-CoV-1 RBD surface. The 80R epitope is shown in blue, the S230 epitope is shown in yellow, the CR3022 epitope is shown in purple and the overlapping m396/F26G19 epitopes are shown in red. (C) The SARS-CoV-1 RBD is shown as a white molecular surface, ACE2 is shown as a transparent red molecular surface, SARS VHH-72 is shown as dark blue ribbons and CR3022 Fab is shown as purple ribbons.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques:

    SARS VHH-72 Bivalency Permits SARS-CoV-2 Pseudovirus Neutralization (A and B) SARS-CoV-1 S (A) and SARS-CoV-2 S (B) VSV pseudoviruses were used to evaluate the neutralization capacity of SARS VHH-72. MERS VHH-55 and PBS were included as negative controls. Luciferase activity is reported in counts per second (c.p.s.). NI, cells were not infected. (C and D) Binding of bivalent VHHs was tested by ELISA against SARS-CoV-1 S (C) and SARS-CoV-2 RBD-SD1 (D). VHH-72-Fc refers to SARS VHH-72 fused to a human IgG1 Fc domain by a GS(GGGGS) 2 linker. VHH-72-Fc (S) is the same Fc fusion with a GS, rather than a GS(GGGGS) 2 , linker. GBP is an irrelevant GFP-binding protein. VHH-72-VHH-72 refers to the tail-to-head construct with two SARS VHH-72 proteins connected by a (GGGGS) 3 linker. VHH-23-VHH-23 refers to the two irrelevant VHHs linked via the same (GGGGS) 3 linker. (E and F) SARS-CoV-1 S (E) and SARS-CoV-2 S (F) pseudoviruses were used to evaluate the neutralization capacity of bivalent VHH-72-Fc. GBP and PBS were included as negative controls. NI, cells were not infected.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: SARS VHH-72 Bivalency Permits SARS-CoV-2 Pseudovirus Neutralization (A and B) SARS-CoV-1 S (A) and SARS-CoV-2 S (B) VSV pseudoviruses were used to evaluate the neutralization capacity of SARS VHH-72. MERS VHH-55 and PBS were included as negative controls. Luciferase activity is reported in counts per second (c.p.s.). NI, cells were not infected. (C and D) Binding of bivalent VHHs was tested by ELISA against SARS-CoV-1 S (C) and SARS-CoV-2 RBD-SD1 (D). VHH-72-Fc refers to SARS VHH-72 fused to a human IgG1 Fc domain by a GS(GGGGS) 2 linker. VHH-72-Fc (S) is the same Fc fusion with a GS, rather than a GS(GGGGS) 2 , linker. GBP is an irrelevant GFP-binding protein. VHH-72-VHH-72 refers to the tail-to-head construct with two SARS VHH-72 proteins connected by a (GGGGS) 3 linker. VHH-23-VHH-23 refers to the two irrelevant VHHs linked via the same (GGGGS) 3 linker. (E and F) SARS-CoV-1 S (E) and SARS-CoV-2 S (F) pseudoviruses were used to evaluate the neutralization capacity of bivalent VHH-72-Fc. GBP and PBS were included as negative controls. NI, cells were not infected.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: Neutralization, Luciferase, Activity Assay, Infection, Binding Assay, Enzyme-linked Immunosorbent Assay, Construct

    Epitope Determination and Biophysical Characterization of MERS VHH-55 and SARS VHH-72 (A) Reactivity of MERS-CoV and SARS-CoV RBD-directed VHHs against the MERS-CoV and SARS-CoV-1 RBD, respectively. A VHH against an irrelevant antigen (F-VHH) was included as a control. Datapoints represent the mean of three replicates and error bars represent the standard errors of the mean. (B) SPR sensorgrams showing binding between the MERS-CoV RBD and MERS VHH-55 (left) and SARS-CoV-1 RBD and SARS VHH-72 (right). Binding curves are colored black, and fit of the data to a 1:1 binding model is colored red.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: Epitope Determination and Biophysical Characterization of MERS VHH-55 and SARS VHH-72 (A) Reactivity of MERS-CoV and SARS-CoV RBD-directed VHHs against the MERS-CoV and SARS-CoV-1 RBD, respectively. A VHH against an irrelevant antigen (F-VHH) was included as a control. Datapoints represent the mean of three replicates and error bars represent the standard errors of the mean. (B) SPR sensorgrams showing binding between the MERS-CoV RBD and MERS VHH-55 (left) and SARS-CoV-1 RBD and SARS VHH-72 (right). Binding curves are colored black, and fit of the data to a 1:1 binding model is colored red.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: SPR Assay, Binding Assay

    Lack of Binding of MERS-CoV and SARS-CoV-Directed VHHs to Non-RBD Epitopes, Related to Figure 1 ELISA data showing binding of the MERS-CoV specific VHHs to the MERS-CoV S1 protein and absence of binding of the MERS-CoV and SARS-CoV specific VHHs against the MERS-CoV NTD and SARS-CoV-1 NTD, respectively. A VHH against an irrelevant antigen (F-VHH) was included as a control.

    Journal: Cell

    Article Title: Structural Basis for Potent Neutralization of Betacoronaviruses by Single-Domain Camelid Antibodies

    doi: 10.1016/j.cell.2020.04.031

    Figure Lengend Snippet: Lack of Binding of MERS-CoV and SARS-CoV-Directed VHHs to Non-RBD Epitopes, Related to Figure 1 ELISA data showing binding of the MERS-CoV specific VHHs to the MERS-CoV S1 protein and absence of binding of the MERS-CoV and SARS-CoV specific VHHs against the MERS-CoV NTD and SARS-CoV-1 NTD, respectively. A VHH against an irrelevant antigen (F-VHH) was included as a control.

    Article Snippet: SARS-CoV-2 RBD with a mouse IgG1 Fc tag (Sino Biological) was immobilized to an anti-mouse IgG Fc capture (AMC) tip (FortéBio) to a response level of 0.5 nm.

    Techniques: Binding Assay, Enzyme-linked Immunosorbent Assay

    Detection and quantification of SARS-CoV-2 RBD- and N- reactive antibodies in pre-pandemic samples. (A) Representative dilution curves of seven pre-pandemic samples with SARS-CoV-2 RBD-reactive antibodies (three subjects per graph). Open and solid symbols represent buffer only coat and SARS-CoV-2 RBD coat, respectively. Arbitrary Units (AU) were calculated as described in Methods and shown beneath the respective isotype graph for diluent only and SARS-CoV-2 RBD coat. AUs for SARS-CoV-2 RBD (B) and N (C) reactive IgM, IgG, and IgA in pre-pandemic samples. Open and solid symbols represent negative and positive results, respectively, as determined by Metric 1. Enumeration of the positive samples for each isotype in the pre-pandemic cohort is shown beneath each graph with percentages of total in parentheses. (D) Correlation between AUs for IgG reactive to SARS-CoV-2 RBD and N (n=32). Values were log-transformed to obtain a parametric distribution. Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test in (B, C) and Pearson’s correlation of normally distributed AU values for (D) .

    Journal: Frontiers in Immunology

    Article Title: Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 via Multi-Parameter Detection

    doi: 10.3389/fimmu.2021.614676

    Figure Lengend Snippet: Detection and quantification of SARS-CoV-2 RBD- and N- reactive antibodies in pre-pandemic samples. (A) Representative dilution curves of seven pre-pandemic samples with SARS-CoV-2 RBD-reactive antibodies (three subjects per graph). Open and solid symbols represent buffer only coat and SARS-CoV-2 RBD coat, respectively. Arbitrary Units (AU) were calculated as described in Methods and shown beneath the respective isotype graph for diluent only and SARS-CoV-2 RBD coat. AUs for SARS-CoV-2 RBD (B) and N (C) reactive IgM, IgG, and IgA in pre-pandemic samples. Open and solid symbols represent negative and positive results, respectively, as determined by Metric 1. Enumeration of the positive samples for each isotype in the pre-pandemic cohort is shown beneath each graph with percentages of total in parentheses. (D) Correlation between AUs for IgG reactive to SARS-CoV-2 RBD and N (n=32). Values were log-transformed to obtain a parametric distribution. Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test in (B, C) and Pearson’s correlation of normally distributed AU values for (D) .

    Article Snippet: SARS-CoV-2 N (Cat# 40588-V08B) and S (Cat# 40591-V08H), NL63 N (Cat# 40641-V07E), 229E N (Cat# 40640-V07E), OC43 N (Cat# 40643-V07E) and HKU1 N (Cat# 40641-V07E) was purchased from Sino Biological.

    Techniques: Transformation Assay, MANN-WHITNEY

    The modified ELISA (BU ELISA) protocol exhibits low background signal at high sample concentration and use of SARS-Cov-2 RBD-recombinant antibody standard curves allows for accurate sample quantification via accounting for OD drift between experimental runs. (A) Dilution curves of buffer only coated wells from five donor samples after using an automated plate washer or the BU ELISA method of multichannel plate washing. Experiment was performed once. (B) Representative dilution curves of buffer only coated wells from 30 subjects, average and range of 1:5 sample dilution for each isotype from all subjects; IgM, IgG, and IgA were detected in individual assays. (C) Representative IgM, IgG, and IgA standard curves from 15 different experimental runs are shown. The average of all runs shown as red triangles.

    Journal: Frontiers in Immunology

    Article Title: Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 via Multi-Parameter Detection

    doi: 10.3389/fimmu.2021.614676

    Figure Lengend Snippet: The modified ELISA (BU ELISA) protocol exhibits low background signal at high sample concentration and use of SARS-Cov-2 RBD-recombinant antibody standard curves allows for accurate sample quantification via accounting for OD drift between experimental runs. (A) Dilution curves of buffer only coated wells from five donor samples after using an automated plate washer or the BU ELISA method of multichannel plate washing. Experiment was performed once. (B) Representative dilution curves of buffer only coated wells from 30 subjects, average and range of 1:5 sample dilution for each isotype from all subjects; IgM, IgG, and IgA were detected in individual assays. (C) Representative IgM, IgG, and IgA standard curves from 15 different experimental runs are shown. The average of all runs shown as red triangles.

    Article Snippet: SARS-CoV-2 N (Cat# 40588-V08B) and S (Cat# 40591-V08H), NL63 N (Cat# 40641-V07E), 229E N (Cat# 40640-V07E), OC43 N (Cat# 40643-V07E) and HKU1 N (Cat# 40641-V07E) was purchased from Sino Biological.

    Techniques: Modification, Enzyme-linked Immunosorbent Assay, Concentration Assay, Recombinant

    SARS-CoV-2 RBD and N reactive IgG in pre-pandemic samples track with IgG recognizing analogous proteins of eCoV strains. (A) AUs of IgG reactive to RBD of NL63 and HKU1 and N of all four eCoV strains (NL63, 2293, OC43, and HKU1). (B) Correlation between SARS-CoV-2 RBD IgG levels with NL63, HKU1 RBD IgG levels in individual subjects. (C) Correlation between SARS-CoV-2 N IgG and NL63, 229E, OC43, and HKU1 N IgG levels, n=30-42. Values were log-transformed to obtain a parametric distribution. Statistical analyses were performed using Pearson’s correlation of normally distributed log transformed AU values in (B, C) and an unpaired non-parametric Mann-Whitney t-test in (A) .

    Journal: Frontiers in Immunology

    Article Title: Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 via Multi-Parameter Detection

    doi: 10.3389/fimmu.2021.614676

    Figure Lengend Snippet: SARS-CoV-2 RBD and N reactive IgG in pre-pandemic samples track with IgG recognizing analogous proteins of eCoV strains. (A) AUs of IgG reactive to RBD of NL63 and HKU1 and N of all four eCoV strains (NL63, 2293, OC43, and HKU1). (B) Correlation between SARS-CoV-2 RBD IgG levels with NL63, HKU1 RBD IgG levels in individual subjects. (C) Correlation between SARS-CoV-2 N IgG and NL63, 229E, OC43, and HKU1 N IgG levels, n=30-42. Values were log-transformed to obtain a parametric distribution. Statistical analyses were performed using Pearson’s correlation of normally distributed log transformed AU values in (B, C) and an unpaired non-parametric Mann-Whitney t-test in (A) .

    Article Snippet: SARS-CoV-2 N (Cat# 40588-V08B) and S (Cat# 40591-V08H), NL63 N (Cat# 40641-V07E), 229E N (Cat# 40640-V07E), OC43 N (Cat# 40643-V07E) and HKU1 N (Cat# 40641-V07E) was purchased from Sino Biological.

    Techniques: Transformation Assay, MANN-WHITNEY

    Older age is associated with lower circulating antibodies reactive with SARS-CoV-2 and eCoV RBD and N antigens. Quantification of IgG reactive to RBD of NL63, HKU1, and SARS-CoV-2 and N of NL63, 229E, OC43, HKU1, and CoV-2 in pre-pandemic samples regrouped based on HIV (A) or SLE (B) disease status or age (C) . Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test.

    Journal: Frontiers in Immunology

    Article Title: Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 via Multi-Parameter Detection

    doi: 10.3389/fimmu.2021.614676

    Figure Lengend Snippet: Older age is associated with lower circulating antibodies reactive with SARS-CoV-2 and eCoV RBD and N antigens. Quantification of IgG reactive to RBD of NL63, HKU1, and SARS-CoV-2 and N of NL63, 229E, OC43, HKU1, and CoV-2 in pre-pandemic samples regrouped based on HIV (A) or SLE (B) disease status or age (C) . Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test.

    Article Snippet: SARS-CoV-2 N (Cat# 40588-V08B) and S (Cat# 40591-V08H), NL63 N (Cat# 40641-V07E), 229E N (Cat# 40640-V07E), OC43 N (Cat# 40643-V07E) and HKU1 N (Cat# 40641-V07E) was purchased from Sino Biological.

    Techniques: MANN-WHITNEY

    Quantification of the relative levels of IgM, IgG, and IgA-reactive SARS-CoV-2-RBD and N antibodies from acute and convalescent SARS-CoV-2 infected subjects. (A) Arbitrary Units (AUs) of SARS-CoV-2 RBD and N reactive IgM, IgG, and IgA of acute and convalescent subjects. Open and solid symbols represent negative and positive results, respectively, as determined by our Metric 1 described in Methods. (B) Correlation between SARS-CoV-2 RBD and N IgM, IgG, and IgA log transformed AUs. Values were log-transformed to obtain a parametric distribution. (C) Quantification of SARS-CoV-2 RBD and N reactive IgM, IgG, and IgA of acute subjects regrouped based on results from Abbott’s SARS-CoV-2 IgG CMIA. Correlation between SARS-CoV-2 RBD (D) and N (E) IgM, IgG, and IgA AUs (log transformed) with the number of days post symptom (dps) onset at time of sample collection for acute subjects. Quantification of SARS-CoV-2 RBD reactive IgM and N reactive IgA (F) and RBD N reactive for IgM, IgG, and IgA (G) for pre-pandemics (n = 19) and Acutes re-classified based on Abbott test results. Light blue bars depict AU range of pre-pandemics for each respective antigen and isotype. Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test in (A, C, F, G) and Pearson’s correlation of normally distributed log transformed AU values in (B, D, E) dps, days post symptom.

    Journal: Frontiers in Immunology

    Article Title: Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 via Multi-Parameter Detection

    doi: 10.3389/fimmu.2021.614676

    Figure Lengend Snippet: Quantification of the relative levels of IgM, IgG, and IgA-reactive SARS-CoV-2-RBD and N antibodies from acute and convalescent SARS-CoV-2 infected subjects. (A) Arbitrary Units (AUs) of SARS-CoV-2 RBD and N reactive IgM, IgG, and IgA of acute and convalescent subjects. Open and solid symbols represent negative and positive results, respectively, as determined by our Metric 1 described in Methods. (B) Correlation between SARS-CoV-2 RBD and N IgM, IgG, and IgA log transformed AUs. Values were log-transformed to obtain a parametric distribution. (C) Quantification of SARS-CoV-2 RBD and N reactive IgM, IgG, and IgA of acute subjects regrouped based on results from Abbott’s SARS-CoV-2 IgG CMIA. Correlation between SARS-CoV-2 RBD (D) and N (E) IgM, IgG, and IgA AUs (log transformed) with the number of days post symptom (dps) onset at time of sample collection for acute subjects. Quantification of SARS-CoV-2 RBD reactive IgM and N reactive IgA (F) and RBD N reactive for IgM, IgG, and IgA (G) for pre-pandemics (n = 19) and Acutes re-classified based on Abbott test results. Light blue bars depict AU range of pre-pandemics for each respective antigen and isotype. Statistical analyses were performed using an unpaired non-parametric Mann-Whitney t-test in (A, C, F, G) and Pearson’s correlation of normally distributed log transformed AU values in (B, D, E) dps, days post symptom.

    Article Snippet: SARS-CoV-2 N (Cat# 40588-V08B) and S (Cat# 40591-V08H), NL63 N (Cat# 40641-V07E), 229E N (Cat# 40640-V07E), OC43 N (Cat# 40643-V07E) and HKU1 N (Cat# 40641-V07E) was purchased from Sino Biological.

    Techniques: Infection, Transformation Assay, MANN-WHITNEY