mouse monoclonal antibody against ace2  (Proteintech)

Journal: Viruses

Article Title: A Novel Antiviral Therapeutic Platform: Anchoring IFN-β to the Surface of Infectious Virions Equips Interferon-Evasive Virions with Potent Antiviral Activity

doi: 10.3390/v17050697

Figure Lengend Snippet: Postulated mechanism underlying the IFNβ-ACE2 fusion protein. ( A ) A SARS-CoV-2- or NL63-infected individual is given the IFNβ-ACE2 via nebulization to the lungs. The sACE2 domain is postulated to bind the Spike protein and coat the virion with a surface array of IFN-β. Based on this strategy, the IFN-β domain will drive IFN-β signaling pathways and antiviral activity in the target cell before viral entry. IFNβ-ACE2 is postulated to provide a more concentrated and targeted approach to delivering IFN-β to the exact site and time of imminent viral infection . ( B ) Schematic diagram of the fusion protein construct consisting of an IFN-β domain and a sACE2(18-611) domain. ( C ) Schematic diagrams of the soluble control proteins: sACE2(18-611), sACE2(18-740), and IFN-β. ( D ) Schematic diagrams of the transmembrane proteins expressed in HEK cells for the ACE2-binding assay. SDS-PAGE gels showing purity of IFNβ-ACE2 ( E ), sACE2(18-740) ( F ), sACE2(18-611) ( G ), and IFN-β ( H ) proteins.

Article Snippet: After washing with PBS with 5% FBS, Vero E6-TMPRSS2-T2A-ACE2 cells were surface-stained with 1:1600 dilution of PE-conjugated mouse anti-human TMPRSS2 (378403, Biolegend) and 1:100 dilution of FITC-conjugated mouse anti-human ACE2 (10108-MM36-F, Sino Biological) for 1 h at 4 °C and then were washed twice with PBS with 5% FBS.

Techniques: Infection, Protein-Protein interactions, Activity Assay, Construct, Control, Binding Assay, SDS Page

Journal: Viruses

Article Title: A Novel Antiviral Therapeutic Platform: Anchoring IFN-β to the Surface of Infectious Virions Equips Interferon-Evasive Virions with Potent Antiviral Activity

doi: 10.3390/v17050697

Figure Lengend Snippet: The IFN-β and sACE2 domains of IFNβ-ACE2 exhibited predicted bioactivities. ( A ) To assay the IFN-β domain, TF-1 cells were incubated with GM-CSF and either IFN-β, sACE2(18-611), or IFNβ-ACE2 then pulsed with [ 3 H]thymidine during the last 24 h of a 3-day culture. The y -axis represents counts per minute (CPM), and error bars represent the SD. Statistical significance was analyzed by use of two-way ANOVA with Tukey’s multiple comparisons test comparing the three control groups to the IFNβ-ACE2 treatment group at each concentration (ns nonsignificant, * p < 0.05, **** p < 0.0001). ( B – E ) To assay the ACE2 domain, HEK-Spike or HEK-control cells were incubated with designated concentrations of either sACE2(18-611) or IFNβ-ACE2 for 1 h at 4 °C. After washing, cells were stained with AF647-conjugated anti-human ACE2 antibody for 1 h at 4 °C. Cells were analyzed for ACE2 binding by flow cytometry. ( B ) Viable, single, live, and GFP + stably transfected cells (parental gate representing all cells in plot) were subgated to show the ACE2 + subset. Representative dot plots show binding of either sACE2(18-611) or IFNβ-ACE2 (2 μM each) to HEK-Spike or HEK-control cells. ( C ) Shown are percentages of ACE2 + HEK-Spike cells (ACE2 + gate/parental gate). ( D ) The MFIs of anti-ACE2 fluorescence are shown for the parental gate. ( E ) Bar graphs show mean percentages of HEK-Spike or HEK-control cells bound to ACE2 (ACE2 + gate/parental gate). Each data point represents the mean value (n = 2), and error bars represent SD. These data are representative of three independent experiments.

Article Snippet: After washing with PBS with 5% FBS, Vero E6-TMPRSS2-T2A-ACE2 cells were surface-stained with 1:1600 dilution of PE-conjugated mouse anti-human TMPRSS2 (378403, Biolegend) and 1:100 dilution of FITC-conjugated mouse anti-human ACE2 (10108-MM36-F, Sino Biological) for 1 h at 4 °C and then were washed twice with PBS with 5% FBS.

Techniques: Incubation, Control, Concentration Assay, Staining, Binding Assay, Flow Cytometry, Stable Transfection, Transfection, Fluorescence

Journal: Viruses

Article Title: A Novel Antiviral Therapeutic Platform: Anchoring IFN-β to the Surface of Infectious Virions Equips Interferon-Evasive Virions with Potent Antiviral Activity

doi: 10.3390/v17050697

Figure Lengend Snippet: The sACE2 domain of IFNβ-ACE2 targeted IFN-β to the surface of NL63. NL63 was incubated at 4 °C with designated concentrations of IFNβ-ACE2, sACE2(18-611), recombinant IFN-β, or IFN-β (Peprotech). After a 1 h incubation, NL63 was washed of any unbound protein using 300kD centrifugal filters. NL63-protein complexes were then added to Vero E6-TMPRSS2-T2A-ACE2 cultures (100 μL) in a 96-well plate. The cells were harvested after a 2-day incubation at 33 °C, stained with LIVE/DEAD Fixable Blue Dead Cell Stain, and then surface-labeled with FITC-conjugated anti-human ACE2 and PE-conjugated anti-human TMPRSS2. After fixation and permeabilization, cells were stained with AF647-conjugated rabbit anti-NL63 nucleocapsid antibody. Cells were then analyzed for viral infection by flow cytometry. Cells were gated on viable, single, and live cells (parental gate) before subgating on nucleocapsid + , ACE2 high , or TMPRSS2 high cells. Shown are representative dot plots (( A , D , I ), x -axis = FSC-A as in ( A )) when NL63 was incubated with 1 nM IFNβ-ACE2 or controls. The IFNβ-ACE2 versus sACE2(18-611) groups were compared based on percentages of nucleocapsid + cells ( B ), percentages of ACE2 high cells ( E ), MFI of anti-ACE2 staining ( F ), percentages of TMPRSS2 high cells ( J ), and MFI of anti-TMRSS2 staining ( K ). The IFNβ-ACE2 versus IFN-β groups were compared based on percentages of nucleocapsid cells ( C ), percentages of ACE2 high cells ( G ), MFI of anti-ACE2 staining ( H ), percentages of TMPRSS2 high cells ( L ), and MFI of anti-TMPRSS2 staining ( M ). Cell percentages were calculated by dividing events in the positive subgate by the parental gate, and MFI values represent all events in the parental gate. Each data point represents the mean value (n = 2), and error bars represent SD. Statistical significance comparing IFN-β and ACE2 treatment groups to the IFNβ-ACE2 treatment group at each concentration was analyzed by use of two-way ANOVA with Tukey’s multiple comparisons test (** p < 0.01, *** p < 0.001, **** p < 0.0001). Statistical significance comparing each protein group at each concentration to blank was analyzed by use of two-way ANOVA with Tukey’s multiple comparisons test (° p < 0.05, °° p < 0.01, °°° p < 0.001, °°°° p < 0.0001). These data are representative of three independent experiments.

Article Snippet: After washing with PBS with 5% FBS, Vero E6-TMPRSS2-T2A-ACE2 cells were surface-stained with 1:1600 dilution of PE-conjugated mouse anti-human TMPRSS2 (378403, Biolegend) and 1:100 dilution of FITC-conjugated mouse anti-human ACE2 (10108-MM36-F, Sino Biological) for 1 h at 4 °C and then were washed twice with PBS with 5% FBS.

Techniques: Incubation, Recombinant, Staining, Labeling, Infection, Flow Cytometry, Concentration Assay

Journal: Viruses

Article Title: A Novel Antiviral Therapeutic Platform: Anchoring IFN-β to the Surface of Infectious Virions Equips Interferon-Evasive Virions with Potent Antiviral Activity

doi: 10.3390/v17050697

Figure Lengend Snippet: The covalent linkage of IFN-β and ACE2 was required for IFN-β targeting to NL63. NL63 was incubated at 4 °C with either IFNβ-ACE2 or the unlinked combination of sACE2(18-611) and IFN-β. After a 1 h incubation, NL63 was repeatedly washed with 300kD centrifugal filters to remove proteins that lacked binding to virions. The retentates, which included virions and virion-bound proteins, were added to Vero E6-TMPRSS2-T2A-ACE2 cells in a 96-well plate. Cells were harvested after a 2-day incubation at 33 °C and stained with LIVE/DEAD Fixable Blue Dead Cell Stain. Cells were surface-stained with PE-conjugated mouse anti-human TMPRSS2 and FITC-conjugated mouse anti-human ACE2. After fixation and permeabilization, cells were stained with AF647-conjugated rabbit anti-NL63 nucleocapsid antibody. Cells were analyzed for viral infection by flow cytometry. Viable, single, and live cells in the parental gate were subgated as the nucleocapsid + subset ( A ), the ACE2 high subset ( C ), and the TMPRSS2 high subset ( F ) as shown for the 1 nM concentration value. Shown are the percentages of nucleocapsid + , ACE2 high , and TMPRSS2 high subsets together with the respective MFI values ( B , D , E ), and ( G , H ), respectively. Cell percentages were calculated by dividing the events in the subset-positive/high subgate by those in the parental gate. MFI values were gated on all viable, single, and live cells (i.e., cells in the parental gate). Each data point represents the mean value (n = 2), and error bars represent SD. Statistical significance of the IFNβ-ACE2 versus the ‘IFN-β + sACE2’ treatment group at each concentration was analyzed by use of two-way ANOVA with Tukey’s multiple comparisons test (** p < 0.01, *** p < 0.001, **** p < 0.0001). Statistical significance was also assessed for treatment groups at each concentration compared to the ‘blank’ control via two-way ANOVA with Tukey’s multiple comparisons test (°° p < 0.01, °°° p < 0.001, °°°° p < 0.0001). These data are representative of three independent experiments.

Article Snippet: After washing with PBS with 5% FBS, Vero E6-TMPRSS2-T2A-ACE2 cells were surface-stained with 1:1600 dilution of PE-conjugated mouse anti-human TMPRSS2 (378403, Biolegend) and 1:100 dilution of FITC-conjugated mouse anti-human ACE2 (10108-MM36-F, Sino Biological) for 1 h at 4 °C and then were washed twice with PBS with 5% FBS.

Techniques: Incubation, Binding Assay, Staining, Infection, Flow Cytometry, Concentration Assay, Control

Journal: Viruses

Article Title: A Novel Antiviral Therapeutic Platform: Anchoring IFN-β to the Surface of Infectious Virions Equips Interferon-Evasive Virions with Potent Antiviral Activity

doi: 10.3390/v17050697

Figure Lengend Snippet: In a non-washed in vitro infection system, IFNβ-ACE2 exhibited enhanced antiviral activity compared to IFN-β alone, ACE2 alone, or the unlinked combination. NL63 was incubated for 1 h at 4 °C with either IFNβ-ACE2, sACE2(18-611), sACE2(18-740), recombinant IFN-β, IFN-β (Peprotech), or the unlinked combination of sACE2(18-611) and IFN-β. In contrast to experiments shown in and , we omitted the virus-washing step. The NL63 + protein mixtures were added to Vero E6-TMPRSS2-T2A-ACE2 cells in a 96-well plate. The cells were harvested after a 2-day incubation at 33 °C and stained with LIVE/DEAD Fixable Blue Dead Cell Stain. Cells were surface-stained with FITC-conjugated mouse anti-human ACE2, were fixed and permeabilized, and then were intracellularly stained with AF647-conjugated rabbit anti-NL63 nucleocapsid antibody. Cells were then analyzed for viral infection by flow cytometry. Cells gated as viable, single, and live cells (parent gate) were subgated to define nucleocapsid + and ACE2 high subsets. Shown ( A , D ) are representative dot plots showing percentages of the nucleocapsid + subset at the 1 pM concentration. Shown ( B , F ) are the percentages of the nucleocapsid + subset for each group over concentrations ranging from 100 fM to 1 μM. Bar graph ( C ) shows mean percentage values of nucleocapsid + cells at the 1 pM concentration. Shown ( E ) are representative dot plots showing percentages of the ACE2 high subset at the 1 pM concentration. Shown ( G ) are the percentages of ACE2 high subset for each group over concentrations ranging from 100 fM to 1 μM. Each data point represents the mean value (n = 2), and error bars represent SD. Statistical significance was analyzed by ( C ) one-way ANOVA with the Dunnett multiple comparisons test or ( F , G ) two-way ANOVA with Tukey’s multiple comparisons test comparing the unlinked combination of IFN-β and ACE2 treatment groups to the IFNβ-ACE2 treatment group at each concentration (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001). These data are representative of three independent experiments.

Article Snippet: After washing with PBS with 5% FBS, Vero E6-TMPRSS2-T2A-ACE2 cells were surface-stained with 1:1600 dilution of PE-conjugated mouse anti-human TMPRSS2 (378403, Biolegend) and 1:100 dilution of FITC-conjugated mouse anti-human ACE2 (10108-MM36-F, Sino Biological) for 1 h at 4 °C and then were washed twice with PBS with 5% FBS.

Techniques: In Vitro, Infection, Activity Assay, Incubation, Recombinant, Virus, Staining, Flow Cytometry, Concentration Assay

Journal: Viruses

Article Title: A Novel Antiviral Therapeutic Platform: Anchoring IFN-β to the Surface of Infectious Virions Equips Interferon-Evasive Virions with Potent Antiviral Activity

doi: 10.3390/v17050697

Figure Lengend Snippet: IFNβ-ACE2 exhibited virus-specific targeting in accordance with viral host receptor specificity . The NL63 or 229E viruses were incubated at 4 °C with either IFNβ-ACE2, sACE2(18-611), IFN-β, or the unlinked combination of IFN-β and sACE2(18-611). After a 1 h incubation, the virus + protein mixtures were washed, and the retentate containing virion–protein complexes was used for infection of Vero E6-TMPRSS2-T2A-ACE2 or A549 cells, respectively, in a 96-well plate ( A , B ). After the washing step, IFNβ-ACE2 or the unlinked combination of IFN-β and sACE2(18-611) were directly added to designated groups ( B ). Alternatively, the virus + protein mixtures were not subjected to a virus-washing step and the mixtures were used for infection of the respective host cells ( C – E ). The cells were harvested after a 2-day incubation and stained with LIVE/DEAD Fixable Blue Dead Cell Stain. After fixation and permeabilization, Vero E6-TMPRSS2-T2A-ACE2 cells were stained with AF647-conjugated rabbit anti-NL63 nucleocapsid antibody and A549 cells were stained with AF647-conjugated rabbit anti-229E nucleocapsid antibody. Cells were then analyzed for viral infection by flow cytometry. Cells were gated on viable, single, and live cells before subgating on nucleocapsid + cells. Shown ( A ) are the percentages of nucleocapsid + cells for each treatment group normalized to the ‘no protein’ control group (1 nM concentrations). ( B ) Bar graph shows mean percentages of nucleocapsid + 229E-infected cells when proteins were or were not added after the washing step (1 nM concentrations). Shown ( C ) are representative dot plots including percentages of nucleocapsid + 229E-infected cells (1 nM concentrations). Shown ( D ) are the percentages of nucleocapsid + cells for each treatment group normalized to the ‘no protein’ group for each virus (1 μM concentrations). Shown ( E ) are the percentages of nucleocapsid + 229E-infected cells for each treatment group at designated concentrations (100 fM to 100 nM). Each data point represents the mean value (n = 2), and error bars represent SD. Statistical significance was analyzed by use of two-way ANOVA with Tukey’s multiple comparisons test comparing the IFN-β and/or ACE2 treatment groups to the IFNβ-ACE2 treatment group at each concentration (unless otherwise noted in the figure) (ns nonsignificant, **** p < 0.0001). Experiments shown are representative of three independent experiments.

Article Snippet: After washing with PBS with 5% FBS, Vero E6-TMPRSS2-T2A-ACE2 cells were surface-stained with 1:1600 dilution of PE-conjugated mouse anti-human TMPRSS2 (378403, Biolegend) and 1:100 dilution of FITC-conjugated mouse anti-human ACE2 (10108-MM36-F, Sino Biological) for 1 h at 4 °C and then were washed twice with PBS with 5% FBS.

Techniques: Virus, Incubation, Infection, Staining, Flow Cytometry, Control, Concentration Assay

Journal: Journal of Advanced Research

Article Title: Key β1-4 galactosylated glycan receptors of SARS-CoV-2 and its inhibitor from the galactosylated glycoproteins of bovine milk

doi: 10.1016/j.jare.2024.12.010

Figure Lengend Snippet: Glycan profiles of the SARS-CoV-2 S1 and the ACE2 receptor. (A) Schematic diagram illustrating the process of preparing antibody-overlay lectin microarrays. (B, C) Scanned images were obtained for the analysis of glycopatterns from the SARS-CoV-2-S1 (B) and ACE2 (C). HEK293-expressing recombinant proteins of S1 and ACE2 were incubated with lectin microarrays. Subsequently, the microarrays were incubated with biotin-labeled primary antibodies and Cy3-labeled streptavidin. The representative lectins that recognized β1-4 galactosylated glycans (ECA and MAL-I), agalactosylated glycans (GSL-II and STL), bisected and bi-antennary N-glycans (PHA-E), oligo-mannose type N-glycans (ConA and HHL), fucosylation (PSA and LCA) and α-2,3 linked sialic acid (MAL-II) were marked with white frames. (D, E) Analysis of glycopatterns on S1 (D) and ACE2 (E). The lectins were classified according to their glycan binding preferences. The NFIs of each lectin were obtained from three biological replicates. The proportion of main types of glycans was calculated by diverging the sum of the NFIs of the lectins that recognized this type of glycan by the total NFIs of all lectins. Blue square: GlcNAc; yellow circle: galactose; yellow square: GalNAc; green circle: mannose; red triangle: fucose; purple diamond: sialic acid. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Article Snippet: The primary antibodies used were as follows: a mouse monoclonal antibody against ACE2 (Proteintech, China), a rabbit polyclonal antibody against the SARS-CoV-2 S protein (ABclonal, China), and a mouse monoclonal antibody against GAPDH (Abways, China).

Techniques: Glycoproteomics, Expressing, Recombinant, Incubation, Labeling, Binding Assay

Journal: Journal of Advanced Research

Article Title: Key β1-4 galactosylated glycan receptors of SARS-CoV-2 and its inhibitor from the galactosylated glycoproteins of bovine milk

doi: 10.1016/j.jare.2024.12.010

Figure Lengend Snippet: Role of N-glycans in the interaction between S1 and ACE2. (A) Schematic diagram illustrating the process of manufacturing the SRAS-CoV-2-related recombinant protein microarrays. (B, C) The N-glycans on S1 of SARS-CoV-2/1 and ACE2 were removed by PNGase F glycosidase. The roles of N-glycans in the interaction between the SARS-CoV-2-S1 /ACE2 (B) and the SARS-CoV-1-S1/ACE2 (C) were evaluated using protein microarrays. Statistical analysis of the relative fluorescence intensities was conducted by comparing the PNGase F-treated S1 and ACE2 to the intact glycosylated protein using one-way ANOVA with Dunnett multiple comparisons. The data were obtained from three biological replicates and presented as the mean ± SD (error bars), and the p values were indicated. (D) MD simulation of the interaction between the trimeric S protein and ACE2. The distances between the N-glycosites and the center of the binding interface (represented by the green globule) within 50 Å were marked with red spheres. Other N-glycosites were marked with yellow spheres. (E) The interactions of glycans at specific sites and GRDs (marked with a red frame) may be involved in the binding of the S protein to ACE2. (F) MD simulated the interactions of glycans at specific sites and GRDs. The distances between the terminal glycans on these sites and the three GRDs on the ACE and S1 subunit were monitored during a 100 ns MD simulation. The distances of N546-GRD1, N322-GRD2, and N53-GRD2 fluctuated between 1 and 15 Å, while the distances of N343-GRD3 and N165-GRD3 fluctuated between 20 and 35 Å. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Article Snippet: The primary antibodies used were as follows: a mouse monoclonal antibody against ACE2 (Proteintech, China), a rabbit polyclonal antibody against the SARS-CoV-2 S protein (ABclonal, China), and a mouse monoclonal antibody against GAPDH (Abways, China).

Techniques: Recombinant, Fluorescence, Binding Assay

Journal: Journal of Advanced Research

Article Title: Key β1-4 galactosylated glycan receptors of SARS-CoV-2 and its inhibitor from the galactosylated glycoproteins of bovine milk

doi: 10.1016/j.jare.2024.12.010

Figure Lengend Snippet: β1-4 galactosylated N-glycans of ACE2 mediated the binding of S1 of SARS-CoV-2 and its variants. (A) Molecular docking analysis of S1 and ACE2 with various saccharides. The potential binding capacities of S1 of SARS-CoV-2 (Wuhan-Hu-1 strain, wild type) and its variants (Delta and Omicron), as well as ACE2, to various saccharides were predicted by molecular docking analysis. The saccharides were listed in columns, S1 and ACE2 were listed in rows. The different binding abilities were represented by the values of binding free energy, which were indicated by the color of each square: red: high affinity, blue: low affinity, Xyl: xylose, Glc: glucose; Man: mannose; GlcNAc: N-acetylglucosamine, GalNAc: N-acetylgalactosamine; SA: sialic acid. (B) Validation of β1-4 galactosylation level in intact and de-β1-4galactosylated ACE2. After β1-4 galactosidase treatment, the level of β1-4 galactosylation on ACE2 was detected by lectin blotting of MAL-I. The protein level of ACE2 served as the control. (C) Scanning images of protein microarrays incubated with 1 μg of intact or de-β1-4galactosylated ACE2. (D) Effect of β1-4 galactosylation of ACE2 on the binding of S1 to ACE2. The relative fluorescence intensities were statistically analyzed by comparing the de-β1-4galactosylated ACE2 to intact ACE2 using an unpaired t test with Welch's correction. The data were obtained from three biological replicates and presented as the mean ± SD (error bars), and the p values were indicated. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Article Snippet: The primary antibodies used were as follows: a mouse monoclonal antibody against ACE2 (Proteintech, China), a rabbit polyclonal antibody against the SARS-CoV-2 S protein (ABclonal, China), and a mouse monoclonal antibody against GAPDH (Abways, China).

Techniques: Binding Assay, Biomarker Discovery, Control, Incubation, Fluorescence

Journal: Journal of Advanced Research

Article Title: Key β1-4 galactosylated glycan receptors of SARS-CoV-2 and its inhibitor from the galactosylated glycoproteins of bovine milk

doi: 10.1016/j.jare.2024.12.010

Figure Lengend Snippet: Evaluation of the ability of free saccharides to block S1 and ACE2 binding. (A, B) Scanning images of protein microarrays. ACE2 was mixed with GalNAc (A) or Galβ1-3GalNAc (B), and the inhibitory effect of saccharides was evaluated using protein microarrays. (C, D) Effect of GalNAc (C) and Galβ-1,3GalNAc (D) on the interaction between S1 of SARS-CoV-2/1 and ACE2. The binding signals were extracted, and the relative fluorescence intensities were compared with those of the controls using one-way ANOVA with Dunnett multiple comparisons. The data were obtained from three biological replicates and presented as the mean ± SD (error bars), and the p values were indicated.

Article Snippet: The primary antibodies used were as follows: a mouse monoclonal antibody against ACE2 (Proteintech, China), a rabbit polyclonal antibody against the SARS-CoV-2 S protein (ABclonal, China), and a mouse monoclonal antibody against GAPDH (Abways, China).

Techniques: Blocking Assay, Binding Assay, Fluorescence

Journal: Journal of Advanced Research

Article Title: Key β1-4 galactosylated glycan receptors of SARS-CoV-2 and its inhibitor from the galactosylated glycoproteins of bovine milk

doi: 10.1016/j.jare.2024.12.010

Figure Lengend Snippet: Evaluation of isolated glycoproteins for the inhibition of S1 and ACE2 binding. (A) The scanned image was obtained from the lectin microarray analysis of glycoproteins isolated from bovine milk. The representative lectins that recognized β1-4 galactosylated glycans (ECA and MAL-I), agalactosylated glycans (GSL-II), bisected N-glycans (PHA-E), high-mannose glycans (ConA), fucosylation (AAL, PSA, and LCA), α2-3 linked sialic acid (MAL-II), and α2-6 linked sialic acid (SNA) were marked with white frames. (B) Analysis of glycopatterns on isolated glycoproteins. The lectins were classified according to their glycan binding preferences. The NFIs of each lectin were obtained from three biological replicates. The proportion of galactosylated glycans was calculated by diverging the sum of the NFIs of the lectins that recognized Gal/GalNAc by the total NFIs. (C, D) Evaluation of the effect of intact and de-sialylated isolated glycoproteins on the interaction between S1 of SARS-CoV-2/1 and ACE2. The intact isolated glycoproteins (C) or de-sialylated isolated glycoproteins (D) were mixed with ACE2 and incubated with protein microarrays. The relative binding intensities of each group were compared with those of the control group, and any significant differences between groups were determined using one-way ANOVA with Dunnett multiple comparisons. The data were obtained from three biological replicates and presented as the mean ± SD (error bars), and the p values were indicated. (E) Inhibition curves for intact isolated glycoproteins (upper) and de-sialylated isolated glycoproteins (lower). Four-parameter inhibition curves were generated, and the particular IC50 values for intact isolated glycoproteins and de-sialylated isolated glycoproteins were indicated in this graph. The data were obtained from three biological replicates and presented as the mean ± SD (error bars).

Article Snippet: The primary antibodies used were as follows: a mouse monoclonal antibody against ACE2 (Proteintech, China), a rabbit polyclonal antibody against the SARS-CoV-2 S protein (ABclonal, China), and a mouse monoclonal antibody against GAPDH (Abways, China).

Techniques: Isolation, Inhibition, Binding Assay, Microarray, Glycoproteomics, Incubation, Control, Generated