Recombinant Human CD20 GST (N-Term) Protein

SDS-Page: Recombinant Human MS4A1/CD20 Protein [H00000931-P01] - 12.5% SDS-PAGE Stained with Coomassie Blue.

• Reactivity: Hu
• Applications: WB, ELISA, MA, AP

Recombinant Human CD20 GST (N-Term) Protein Summary

• Description: A recombinant protein with GST tag at N-terminal corresponding to the amino acids 1-297 of Human MS4A1
  
  

  Source: Wheat Germ (in vitro)

  Amino Acid Sequence: MTTPRNSVNGTFPAEPMKGPIAMQSGPKPLFRRMSSLVGPTQSFFMRESKTLGAVQIMNGLFHIALGGLLMIPAGIYAPICVTVWYPLWGGIMYIISGSLLAATEKNSRKCLVKGKMIMNSLSLFAAISGMILSIMDILNIKISHFLKMESLNFIRAHTPYINIYNCEPANPSEKNSPSTQYCYSIQSLFLGILSVMLIFAFFQELVIAGIVENEWKRTCSRPKSNIVLLSAEEKKEQTIEIKEEVVGLTETSSQPKNEEDIEIIPIQEEEEEETETNFPEPPQDQESSPIENDSSP

• Preparation Method: in vitro wheat germ expression system
• Details of Functionality: This protein was produced in an in vitro wheat germ expression system that should preserve correct conformational folding that is necessary for biological function. While it is possible that this protein could display some level of activity, the functionality of this protein has not been explicitly measured or validated.
• Source: Wheat germ
• Protein/Peptide Type: Recombinant Protein
• Gene: MS4A1
• Purity: >80% by SDS-PAGE and Coomassie blue staining

Applications/Dilutions

• Dilutions:
  • ELISA
  • Immunoaffinity Purification
  • Protein Array
  • Western Blot
• Theoretical MW: 58.41 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.

Packaging, Storage & Formulations

• Storage: Store at -80C. Avoid freeze-thaw cycles.
• Buffer: 50 mM Tris-HCl, 10 mM reduced Glutathione, pH 8.0 in the elution buffer.
• Preservative: No Preservative
• Purity: >80% by SDS-PAGE and Coomassie blue staining

Notes

This product is produced by and distributed for Abnova, a company based in Taiwan.

Alternate Names for Recombinant Human CD20 GST (N-Term) Protein

• B1
• B-lymphocyte antigen CD20
• B-lymphocyte cell-surface antigen B1
• B-lymphocyte surface antigen B1
• Bp35
• Bp35MGC3969
• CD20 antigen
• CD20 receptor
• CD20
• CD20S7
• CVID5
• LEU-16
• Leukocyte surface antigen Leu-16
• Ly-44
• Membrane-spanning 4-domains subfamily A member 1
• membrane-spanning 4-domains, subfamily A, member 1
• MS4A1
• MS4A2
• S7

Background

CD20 is a non-glycosylated phosphoprotein that is expressed on the surface of normal and malignant B cells and functions in mediating calcium transport and B cell differentiation (1,2). CD20 is encoded by the membrane-spanning 4-domain family A member 1 (MS4A1) gene and, in humans, is located on chromosome 11q12 (1). The CD20 protein is 297 amino acids (aa) in length with a theoretical molecular weight (MW) of 33 kDa (1,2). Structurally, the CD20 protein has four membrane-spanning domains, two extracellular loop domains, and intracellular N- and C-terminal domains (1,2). CD20 is expressed at specific stages of B cell maturation including pre-B cells, mature naive and activated B cells, and memory B cells, but is absent from plasmablasts and plasma cells (1,3,4). Expression of CD20 is often increased on malignant B cells associated with various B cell disorders such as chronic lymphocytic leukemia (CLL), multiple sclerosis (MS), and rheumatoid arthritis (2-4). Anti-CD20 monoclonal antibody (mAb)-based therapies have become an appealing target for treating these immune-related disorders and cancers (1-5). Rituximab, a chimeric mAb, was the first FDA approved CD20 monoclonal antibody for the treatment of non-Hodgkin's lymphoma that is now commonly used to treat MS (2,3). Since its initial approval in 1997, several other chimeric and humanized anti-CD20 mAbs have been developed including Ofatumumab, Ublituximab, and Obinutuzumab (1-5). B cell depletion via CD20 mAbs can occur under different mechanisms such as antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), complement-dependent cytotoxicity (CDC), and direct induction of apoptosis (1-4). Many ongoing studies are focused on combination therapies with CD20 mAbs as an addition to chemotherapy, B cell receptor (BCR) signaling inhibitors, or BH3 mimetics (1,2,4). Additionally, the effects of bispecific antibodies and CD20 chimeric antigen receptor (CAR) T cell therapies are under investigation for the treatment of B cell malignancies (4,5).

References

1. Pavlasova G, Mraz M. The regulation and function of CD20: an "enigma" of B-cell biology and targeted therapy. Haematologica. 2020; 105(6):1494-1506. https://doi.org/10.3324/haematol.2019.243543

2. Payandeh Z, Bahrami AA, Hoseinpoor R, et al. The applications of anti-CD20 antibodies to treat various B cells disorders. Biomed Pharmacother. 2019; 109:2415-2426. https://doi.org/10.1016/j.biopha.2018.11.121

3. Margoni M, Preziosa P, Filippi M, Rocca MA. Anti-CD20 therapies for multiple sclerosis: current status and future perspectives. J Neurol. 2022; 269(3):1316-1334. https://doi.org/10.1007/s00415-021-10744-x

4. Klein C, Jamois C, Nielsen T. Anti-CD20 treatment for B-cell malignancies: current status and future directions. Expert Opin Biol Ther. 2021; 21(2):161-181. https://doi.org/10.1080/14712598.2020.1822318

5. Sharman JP. Targeting CD20: teaching an old dog new tricks. Hematology Am Soc Hematol Educ Program. 2019; 2019(1):273-278. https://doi.org/10.1182/hematology.2019000031

Limitations

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Peptides and proteins are guaranteed for 3 months from date of receipt.

Publications for CD20 Recombinant Protein (H00000931-P01)(2)

Publications using H00000931-P01

• Nasir S, Shahryar N, Zhanjun G et al. Isolation and characterization of human anti-CD20 single-chain variable fragment (scFv) from a Naive human scFv library. Med Oncol. 2022-08-23 [PMID: 35999405]
• Chen K, Page JG, Schwartz AM et al. False-positive immunogenicity responses are caused by CD20+ B cell membrane fragments in an anti-ofatumumab antibody bridging assay. J Immunol Methods. 2013-04-29 [PMID: 23639298]

FAQs for CD20 Recombinant Protein (H00000931-P01). (Showing 1 - 4 of 4 FAQs).

1. We are looking for human CD20 purified protein for use in ELISA. Can you estimate the level of purity for this protein? Cat # H000000931-P01. Also what is the difference between recombinant and partial recombinant H00000931-Q01-25ug.
   • The purity of H00000931-P01 is usually >80%. As for your 2nd question: the partial recombinant protein is made up of amino acids 210 - 297, with a GST-tag at the N-terminal. The full length recombinant protein is the entire protein with the GST-tag.
2. I am developing mass spectrometry tools to study the interactions between antibodies and antigens and to accomplish epitope mapping. I currently have Rituximab antibody. Do you know if it will bind to your recombinant CD20 protein? Is this the best CD20 sample you have for such a study?
   • The CD20 protein you are referring to, H00000931-P01 is an Abnova protein, a Taiwanese company that we distribute for. This is a full length protein which does have a GST tag at the N-terminus and was expressed using the in vitro wheat germ expression system. This expression system allows for proper protein folding and activity however, does not glycosylate the proteins. Due to the fact that this protein was not used with the antibody you are referring to I cannot comment on the usage of these 2 products together. Our routine applications that we validate our products for includes Western blot, IHC, Immunofluorescence, IP, ELISA and flow. We cannot predict if this recombinant protein would work for your application.
3. Have you tested binding activity of this protein to Rituximab ?
   • Our CD20 recombinant protein with catalogue number H00000931-P01 is produced by a Taiwanese company called Abnova, for whom we distribute. We do not perform any in-house testing or development of Abnova's products. Unless specifically stated, Abnova do not test the activity of their recombinant proteins. The proteins are produced in a cell-free wheat germ system and have an N-terminal 26kDa GST-tag. Due to the nature of the expression system, the proteins do not always undergo the same folding and post-translational modifications that they might undergo in an endogenous cell. We do not recommend this protein for use in functional assays and do not guarantee it for this use.
4. As per the mentioned detail of CD20 recombinant protein (Cat No-#H00000931-P01), We need some check points. Does the product bind to Rituximab Antibody or it shows any activity in Surface plasmon resonance analysis?
   • The CD20 recombinant protein, H00000931-P01, is made by Abnova, a company based in Taiwan for whom we distribute. We only distribute this product and all testing information comes directly from Abnova. Unfortunately, I do not see that Abnova has tested this product with any Rituximab Antibody, so I do not have any information as to whether this protein binds. This protein is not active, and we can only guarantee this proteins's performance in the applications listed on the datasheet. Unfortunately, Abnova does not have any data on this protein's use in surface plasmon resonance. I apologize for any inconvenience.

Bioinformatics

• Gene Symbol: MS4A1