Code | CSB-MP015007HU |
MSDS | |
Size | $570 |
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This recombinant human CD20 (MS4A1) protein is produced as a virus-like particle (VLP) in mammalian cells, encompassing the full-length (amino acids 1-297) with a C-terminal 10×His tag for enhanced purification and detection. The VLP formulation mimics native membrane presentation while maintaining excellent purity (>90% by SDS-PAGE) and low endotoxin levels (<1.0 EU/μg, LAL method).
Functional analysis demonstrates that the recombinant MS4A1 protein specifically binds to the anti-CD20 recombinant antibody (CSB-RA015007A1HU) in ELISA format (EC50: 3.243-7.085 ng/mL), validating its structural integrity and biological relevance. The VLP structure provides multiple CD20 epitopes in their native conformation, making this preparation particularly valuable for the development and evaluation of CD20-targeting therapeutics, vaccine research against B-cell malignancies, structural studies of antibody-CD20 interactions, and B-cell immunology research.
The mammalian expression system ensures proper post-translational modifications, while the lyophilized form offers convenient storage and handling. This MS4A1 VLP represents an advanced tool for cancer research, particularly in studies of B-cell lymphomas and therapeutic antibody development, combining the benefits of recombinant protein technology with native-like membrane presentation.
Human CD20 protein, also known as MS4A1, is a transmembrane protein predominantly expressed on B-lymphocytes. It has significant implications in both normal immune function and pathological conditions, particularly in hematological malignancies such as lymphomas. Structurally, CD20 is composed of four hydrophobic transmembrane domains, with both N- and C-termini located in the cytoplasm, which is critical for its role in cellular signaling and receptor organization on the B-cell surface [1][2][3].
CD20 functions primarily as a regulator of B-cell activation, influencing processes such as cell proliferation, differentiation, and immunoglobulin secretion. Unlike many surface proteins, CD20 does not have a known natural ligand, suggesting its function is primarily cell-intrinsic [3][4]. It has been identified as a calcium-permeable cation channel that plays a vital role in calcium signaling, essential for B-cell activation [5][6]. The involvement of CD20 in calcium mobilization indicates its crucial role in initial B-cell activation, which subsequently regulates various downstream signaling pathways essential for immune responses [4][7].
The presence of CD20 on B cells makes it an important target for therapeutic interventions, particularly in the form of monoclonal antibodies like rituximab. The binding of these antibodies to CD20 induces the death of B cells through mechanisms such as complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) [8][9]. These effects are particularly relevant in the context of treatments for B-cell malignancies, where anti-CD20 therapies have shown significant efficacy [10][11]. For instance, studies have shown that anti-CD20 antibodies can profoundly impact the clinical outcomes in B-cell neoplasms by depleting CD20-positive cells, leading to therapeutic remission in many patients [12][10].
Furthermore, CD20 expression is relatively restricted, absent in terminally differentiated plasma cells and expressed at various stages of B-cell development, including pre-B, immature, mature, and activated B cells [1][13]. This selective expression pattern makes CD20 a useful biomarker for identifying B-cell populations in clinical diagnostics and research settings. Understanding the functional implications of CD20's activity and its interaction with therapeutic antibodies continues to drive research aimed at improving outcomes in B-cell-related diseases [14].
References:
[1] T. Kuijpers, R. Bende, et al. Cd20 deficiency in humans results in impaired t cell–independent antibody responses. Journal of Clinical Investigation, vol. 120, no. 1, p. 214-222, 2010. https://doi.org/10.1172/jci40231
[2] C. Adra, J. Lélias, et al. Cloning of the cdna for a hematopoietic cell-specific protein related to cd20 and the beta subunit of the high-affinity ige receptor: evidence for a family of proteins with four membrane-spanning regions. Proceedings of the National Academy of Sciences, vol. 91, no. 21, p. 10178-10182, 1994. https://doi.org/10.1073/pnas.91.21.10178
[3] M. Cragg, C. Walshe, А. Иванов, & M. Glennie. The biology of cd20 and its potential as a target for mab therapy. p. 140-174, 2004. https://doi.org/10.1159/000082102
[4] F. Förster, A. Singla, S. Arora, R. Schmidt, & R. Jacobs. Cd20+ t cell numbers are decreased in untreated hiv-1 patients and recover after haart. Immunology Letters, vol. 146, no. 1-2, p. 74-78, 2012. https://doi.org/10.1016/j.imlet.2012.05.004
[5] H. Li, L. Ayer, J. Lytton, & J. Deans. Store-operated cation entry mediated by cd20 in membrane rafts. Journal of Biological Chemistry, vol. 278, no. 43, p. 42427-42434, 2003. https://doi.org/10.1074/jbc.m308802200
[6] M. Kanzaki, L. Nie, H. Shibata, & I. Kojima. Activation of a calcium-permeable cation channel cd20 expressed in balb/c 3t3 cells by insulin-like growth factor-i. Journal of Biological Chemistry, vol. 272, no. 8, p. 4964-4969, 1997. https://doi.org/10.1074/jbc.272.8.4964
[7] K. Kläsener, J. Jellusova, et al. Cd20 as a gatekeeper of the resting state of human b cells. Proceedings of the National Academy of Sciences, vol. 118, no. 7, 2021. https://doi.org/10.1073/pnas.2021342118
[8] K. Yoshinaga, M. Araki, et al. Low‐dose rituximab induction therapy is effective in immunological high‐risk renal transplantation without increasing cytomegalovirus infection. International Journal of Urology, vol. 27, no. 12, p. 1136-1142, 2020. https://doi.org/10.1111/iju.14382
[9] J. Teeling, W. Mackus, et al. The biological activity of human cd20 monoclonal antibodies is linked to unique epitopes on cd20. The Journal of Immunology, vol. 177, no. 1, p. 362-371, 2006. https://doi.org/10.4049/jimmunol.177.1.362
[10] E. Wilk, T. Witte, et al. Depletion of functionally active cd20+ t cells by rituximab treatment. Arthritis & Rheumatism, vol. 60, no. 12, p. 3563-3571, 2009. https://doi.org/10.1002/art.24998
[11] M. Cragg, S. Morgan, et al. Complement-mediated lysis by anti-cd20 mab correlates with segregation into lipid rafts. Blood, vol. 101, no. 3, p. 1045-1052, 2003. https://doi.org/10.1182/blood-2002-06-1761
[12] M. Weber, T. Prod’homme, et al. B‐cell activation influences t‐cell polarization and outcome of anti‐cd20 b‐cell depletion in central nervous system autoimmunity. Annals of Neurology, vol. 68, no. 3, p. 369-383, 2010. https://doi.org/10.1002/ana.22081
[13] W. Sun, N. Zhang, Y. Zhang, Z. Shao, L. Gong, & W. Wei. Immunophenotypes and clinical features of lymphocytes in the labial gland of primary sjogren's syndrome patients. Journal of Clinical Laboratory Analysis, vol. 32, no. 9, 2018. https://doi.org/10.1002/jcla.22585
[14] A. Pröbstel and S. Hauser. Multiple sclerosis: b cells take center stage. Journal of Neuro-Ophthalmology, vol. 38, no. 2, p. 251-258, 2018. https://doi.org/10.1097/wno.0000000000000642
Applications : Antigen
Review: I used the CSB-MP015007HU protein for an ELISA experiment, and the EC50 was measured to be 3.628-5.735 ng/ml, indicating good protein activity. The effect of flow cytometric analysis is also very good, with good repeatability and stable results. Product procurement is convenient and cost-effective.
By Anonymous
Applications : Binding assay/Protein-protein interaction
Review: After receiving the product, we conducted an ELISA experiment with the anti-CD20 (MS4A1) antibody, and the EC50 was 3.628-5.735 ng/ml, showing good binding activity. CD20 (MS4A1) has four times transmembrane domains, I have contacted many companies, but they can\'t express it successfully. CUSABIO expresses full-length proteins and has complete biological activity, which is very powerful!
By Anonymous
Why does the CD20 protein is almost invisible in the tube?
All CUSABIO proteins don’t contain carrier protein or other additives, such as bovine serum albumin (BSA), human serum albumin (HSA), and sucrose. When freeze-drying the lowest salt content solution, it often does not form a white grid structure, but a trace amount of protein deposits within the tube, forming a thin transparent or invisible protein layer.
Tips: Before opening the lid, we recommend centrifuging the tube in a small centrifuge for 20-30 seconds to aggregate the protein attached to the inside wall or cap of the tube to the bottom of the tube. Our quality control steps ensure that the amount of protein contained in each tube is accurate. Although sometimes you can’t see the protein powder, the protein content in the tube is still very accurate.
Does this CD20 protein soluble?
Yes, it is. We offer five expression systems: E. coli, Yeast, Baculovirus, Mammalian cell, and Cell-Free (in vitro E.coli). Among them, yeast only has supernatant expression, and the protein expressed in the supernatant must be a soluble protein.
The E. coli, Baculovirus, Mammalian cell, and Cell-Free (in vitro E.coli) have both supernatant expression and inclusion body expression. As long as the protein is expressed in the supernatant, it must be soluble. If it is expressed in the inclusion body, we will also take a variety of methods to refold it and finally ensure that all the proteins we provide are soluble.
Why should we add the protective agent to the protein solution before lyophilization? What's the general protective agent? Which kind of protective agent do you usually add?
The protective agent is used in the process of freeze-drying and storage to protect the protein.
Commonly used protective agents or stabilizers include saccharides, polyols, polymers, surfactants, some proteins, and amino acids, etc. We usually add 6% (mass ratio by volume) of trehalose as lyoprotectant. Trehalose can significantly prevent the alter of the protein secondary structure and the extension and aggregation of proteins during freeze-drying process. Mannitol is also a universal applied lyoprotectant and filler, which can reduce the aggregation of certain proteins after lyophilization.
Tips: For the majority of proteins, they can be only stored at 4 ℃ for a short term (about a week) after being resuspended. If you want long-term preservation, they should be formulated as a diluent (which must contain a carrier protein, such as 0.1% BSA, 5% HSA, or 10% FBS), and then repackaged and frozen at -20℃ or -80℃. Be sure to avoid repeated freezing and thawing. Because each freezing and thawing cycle will cause part of the protein inactivation.
Is the CD20 protein free of animal components?
Yes, it is. We guarantee that all proteins produced by CUSABIO are 100% animal-free, as we do not use any animal components in our raw materials and no animal components are added during the production process. Serum-free media is also used in the expression of our mammalian proteins. We can provide a declaration of no animal component if it is required.
Is this protein cell-component-free?
The protein expressed in the body, regardless of the system, is expressed by cell, and the cell expression can be divided into intracellular expression and secretory expression.
The E. coli system only has intracellular expression and needs to be broken, so the cell components are relatively more secreted than other systems.
Yeast, Baculovirus, and Mammalian cell systems can be expressed both in the cell and in the secretory expression, and the secreted expression of the protein component remains relatively less intracellular.
In vitro expression means that cell-free and the E. coli cell extract is also added, so that the cell component remains.
Therefore, no matter which expression system and which way the protein is expressed, there will be residual cell components, but we finally use affinity chromatography to purify. In theory, the residual of the cell components will be very small, but 100% of no residue cannot be guaranteed. (Nor does any companies dare to guarantee).
Can you offer aseptic manufacture processing?
Yes, we can offer an aseptic processing service and it is free of charge, but you should remark this information when placing the order. We've performed aseptic processing for liquid protein before lyophilization, but there may exist contamination during lyophilization process. To clarify, lyophilized proteins can’t guarantee aseptic processing for the whole manufacture process.
Can you remove the tag?
Not all protein tags can be removed as some proteins will be very unstable after tag removal. Please contact us in advance if you need to remove the tag which takes 2-3 business days. If we succeed in removing the tag, we will charge for extra cost for it. If we fail in removing the tag, we won't charge for any extra cost and remark this information in the datasheet as follows "Note: The laboratory determined that the tag on your protein could not be removed with standard laboratory procedures. Your protein is being supplied with the tag intact."
What is the concentration range of the protein? How do you determine the quantity of it?
The protein concentration of each batch won't be exactly the same but we could guarantee 0.1-5.0 mg/mL concentration for our expression system. If you have a special requirement for protein concentration, please contact us in advance.
There are three methods of protein concentration detection: bradford method, BCA method, A280 method. Each of these three methods has interference buffer components. According to the composition of buffer, the bradford method is the most popular with laboratories including ours, and the concentration detection range is 0.1-5 mg/mL. We also use BCA method in times.