Active Recombinant Human CR2 protein(Met1-Arg971), His-tagged

• Cat.No.: CR2-3186H
• Product Overview: Recombinant Human CD21 isoform A (P20023-1) extracellular domain (Met 1-Arg 971) was expressed in HEK293, with a carboxy-terminal polyhistidine tag.

Specification

• Species: Human
• Source: HEK293
• Tag: His
• Protein Length: Met1-Arg971
• Form: Lyophilized from sterile PBS, pH 7.4. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween80 are added as protectants before lyophilization.
• Bio-activity: Measured by its binding ability in a functional ELISA. Immobilized Human CD21 His at 2 μg/ml (100 μl/well) can bind Human Annexin VI/ANXA6 His, Biotinylated, the EC50 of Human Annexin VI/ANXA6 His, Biotinylated is 250-900 ng/mL.
• Molecular Mass: The secreted recombinant human CD21 pro form consists of 962 amino acids with the predicted molecular mass of 106 kDa. As a result of glycosylation, the apparent molecular mass of rhCD21 is approximately 110-120 kDa in SDS-PAGE under reducing conditions.
• Endotoxin: < 1.0 EU per μg of the protein as determined by the LAL method.
• Purity: > 95 % as determined by SDS-PAGE
• Storage: Samples are stable for up to twelve months from date of receipt at -20°C to -80°C. Store it under sterile conditions at -20°C to -80°C. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.
• Reconstitution: It is recommended that sterile water be added to the vial to prepare a stock solution of 0.2 ug/ul. Centrifuge the vial at 4°C before opening to recover the entire contents.

Gene Information

• Gene Name: CR2 complement component (3d/Epstein Barr virus) receptor 2 [ Homo sapiens ]
• Official Symbol: CR2
• Synonyms: CR2; complement component (3d/Epstein Barr virus) receptor 2; complement receptor type 2; CD21; EBV receptor; complement C3d receptor; epstein-Barr virus receptor; CR; C3DR; SLEB9
• Gene ID: 1380
• mRNA Refseq: NM_001006658
• Protein Refseq: NP_001006659
• MIM: 120650
• UniProt ID: P20023

Case Study

Case 1: Jin H, et al. J Immunol. 2023

Chickens have a version of the complement receptor type 2 (CR2), an immune player in birds, that connects different immunity components. This chicken CR2 binds well with chicken C3d, an important part of their immune response. It's smaller than human CR2 but is significant in their immune organs and changes with infections, serving as a key immune marker for chickens.

Fig1. Measurement of the KD for chCR2 and chC3d by SPR technology.

Fig2. The position of the epitope recognized by the chCR2 mAb at aa 258-269 identified by WB with the anti-chCR2 mAb.

Case 2: Cruickshank MN, et al. Mol Immunol. 2012

Systemic lupus erythematosus (SLE) is a tricky autoimmune disease, largely influenced by genetics. One genetic factor linked to higher SLE risk involves a three-SNP pattern in the CR2 gene. On the flip side, a different SNP pattern offers some protection. A specific SNP, rs3813946, found in the CR2 gene's 5' untranslated region, changes how the gene behaves in cell lines, whether temporarily or permanently introduced. This SNP tweaks gene function by affecting how accessible the surrounding DNA is for transcription factors, making it an important piece in the gene's regulation and its link to lupus.

Fig1. UV crosslinking with Raji and K562 cytoplasmic (CE) and nuclear (NE) extracts identified two proteins bound to both CR2 transcripts in a sequence-specific manner.

Fig2. Evidence that C/EBP β, PAX5 and MAZ interacts with the CR2 5` UTR in Raji cells.

Application

Recombinant CR2 protein, crafted through cutting-edge recombinant DNA technology, is truly making a splash in medical research. By producing this protein in the lab, researchers have unlocked a crucial tool to delve deeper into the immune system, particularly in the context of diseases like lupus. This lab-created version of complement receptor 2 offers scientists a way to study how CR2 interacts with the immune system without needing to tinker directly with the natural processes of the body. Think of it as having a reliable "stand-in" that mimics the real action, allowing scientists to investigate immune functions more freely and accurately. In addition to its research uses, recombinant CR2 also holds potential as a therapeutic breakthrough. Picture a scenario where we could develop targeted treatments for autoimmune diseases, where the body's defense mechanisms unfortunately start attacking its own tissues. By leveraging recombinant CR2, researchers are looking at ways to modulate immune responses, paving the way for innovative treatments that might bring relief and better management for individuals affected by such conditions. The ultimate goal is to create therapies that are not only more effective but also come with fewer side effects. It's an exciting time in biotechnology, as recombinant CR2 opens up new possibilities in both understanding and treating complex immune disorders, marking a significant step forward in medical research and potential therapeutic application.

Fig1. Human CR2 (CD21) involved in intracellular signaling events. (Anna Erdei, 2021)