CD81 Human

CD81 is a widely expressed cell-surface protein involved in a variety of biological responses. It is related to the adhesion, morphology, activation, proliferation, and differentiation of B cells, T cells, and other cell types . On B cells, CD81 forms a complex with CD21, CD19, and Leu13, which reduces the threshold for B cell activation via the B cell receptor by bridging antigen-specific recognition and CD21-mediated complement recognition .

Recombinant human CD81 is produced using DNA sequences encoding the human CD81 protein. These sequences are expressed in host cells, such as HEK293 cells, to produce the protein . The recombinant human CD81 protein typically comprises 91 amino acids and has a predicted molecular mass of approximately 9.9 kDa . The protein is often lyophilized from sterile phosphate-buffered saline (PBS) and may include protectants like trehalose, mannitol, and Tween80 before lyophilization .

Recombinant CD81 is used in various research applications, including studies on cell signaling, immune response, and viral infections. For instance, CD81 has been shown to play a role in the trafficking of the SARS-CoV-2 Spike protein, which is crucial for understanding the virus’s maturation pathway and developing effective vaccines .

Recombinant CD81 proteins are generally stable for up to twelve months when stored at -20°C to -80°C under sterile conditions . It is recommended to aliquot the protein to avoid repeated freeze-thaw cycles, which can degrade the protein .