The spike (S) glycoprotein of coronaviruses is essential for binding of the virus to the host cell at the beginning of the infection process. The severe acute respiratory syndrome-coronavirus (SARS-CoV) spike (S) glycoprotein is responsible for membrane fusion and is therefore required for virus entry and cell fusion. The target protein is also a major immunogen and a possible target for entry inhibitors.
The SARS-CoV-2 spike (S) protein is a large type I transmembrane protein composed of two subunits, S1 and S2. The S1 subunit contains a receptor-binding domain (RBD) responsible for binding to the host cell receptor angiotensin-converting enzyme 2 (ACE2). The S2 subunit mediates fusion between the viral and host cell membranes. The S1 RBD protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity.
SARS-CoV-2 Spike S1 (RBD) recognizes hACE2 (ECD) with an affinity constant of 1 nM as verified by biolayer interferometry
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SARS-CoV-2 Spike S1 (RBD) is highly pure and forms stable monomers of 28 kDa as verified by SEC
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Biolayer interferometry binding analysis (green lines) of hACE2 (ECD, processed), Tag-free to immobilized SARS-CoV-2 Spike S1 (RBD), His-Tag on Ni-NTA Dip and Read™ Biosensors. Grey lines correspond to a global fit of the data using a 1:1 binding model. Device: Octet RED96e, ForteBio.
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Size exclusion chromatography (SEC) of purified SARS-CoV-2 Spike S1 (RBD), His-Tag protein, determination of elution profile by absorbance at 280 nm (blue line).
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Fluorescence chromatogram
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Activity of SARS-CoV-2 S1(RBD)
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Analysis of released N-glycans by HILIC (example data). More and lot specific analytical data available on request (provided by our partner Biofidus AG).
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Activity of different SARS-CoV-2 S1(RBD) lots was determined using a Sandwich-ELISA with antibodies from Sino Biological Europe GmbH (coat: #40150-D003 and detection: #40150-D001-H).
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Stability during storage at 4°C
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Stability during storage at 4°C determined by functional ELISA (binding to hACE2 (ECD) – Cat# P2020-016; detection by mAb CR3022).
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SDS-PAGE/Coll. Coomassie
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Histogram of marked lane in gel picture
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