膜杰作
Star Staining
分子别名（Synonym）
Spike,S protein RBD,Spike glycoprotein Receptor-binding domain,S glycoprotein RBD,Spike protein RBD
表达区间及表达系统（Source）
Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (SPD-C82E9) is expressed from human 293 cells (HEK293). It contains AA Arg 319 - Lys 537 (Accession # QHD43416.1).
Predicted N-terminus: Arg 319
Request for sequence
蛋白结构（Molecular Characterization）
This protein carries a polyhistidine tag at the C-terminus, followed by an Avi tag (Avitag™).
The protein has a calculated MW of 28.2 kDa. The protein migrates as 33-36 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.
标记（Labeling）
Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.
蛋白标记度（Protein Ratio）
Passed as determined by the HABA assay / binding ELISA.
内毒素（Endotoxin）
Less than 1.0 EU per μg by the LAL method.
纯度（Purity）
>95% as determined by SDS-PAGE.
>90% as determined by SEC-MALS.
制剂（Formulation）
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4 with trehalose as protectant.
Contact us for customized product form or formulation.
重构方法（Reconstitution）
Please see Certificate of Analysis for specific instructions.
For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.
存储（Storage）
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
- -20°C to -70°C for 12 months in lyophilized state;
- -70°C for 12 months under sterile conditions after reconstitution.
电泳（SDS-PAGE）
Biotinylated SARS-CoV-2 Spike RBD, His,Avitag on SDS-PAGE under reducing (R) condition. The gel was stained with Coomassie Blue. The purity of the protein is greater than 95% (With Star Ribbon Pre-stained Protein Marker).
SEC-MALS
The purity of Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (Cat. No. SPD-C82E9) is more than 90% and the molecular weight of this protein is around 33-43 kDa verified by SEC-MALS.
Report
活性（Bioactivity）-ELISA
Immobilized Human ACE2, Fc Tag (Cat. No. AC2-H5257) at 2 μg/mL (100 μL/well) can bind Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (Cat. No. SPD-C82E9) with a linear range of 4-125 ng/mL (QC tested).
Protocol
Immobilized Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (Cat. No. SPD-C82E9) at 1 μg/mL (100 μL/well) on streptavidin precoated (0.5 μg/well) plate, can bind Anti-SARS-CoV-2 Neutralizing Antibody, Human IgG1 (Cat. No. SAD-S35) with a linear range of 0.1-3 ng/mL (Routinely tested).
Protocol
活性（Bioactivity）-BLI
Loaded Biotinylated SARS-CoV-2 Spike RBD, His,Avitag (Cat. No. SPD-C82E9) on SA Biosensor, can bind Human ACE2, His Tag (Cat. No. AC2-H52H8) with an affinity constant of 1.14 nM as determined in BLI assay (ForteBio Octet Red96e) (Routinely tested).
Protocol
背景（Background）
It's been reported that Coronavirus can infect the human respiratory epithelial cells through interaction with the human ACE2 receptor. The spike protein is a large type I transmembrane protein containing two subunits, S1 and S2. S1 mainly contains a receptor binding domain (RBD), which is responsible for recognizing the cell surface receptor. S2 contains basic elements needed for the membrane fusion.The S protein plays key parts in the induction of neutralizing-antibody and T-cell responses, as well as protective immunity.
