膜杰作
Star Staining
分子别名（Synonym）
MS4A1,CD20,MS4A-1
表达区间及表达系统（Source）
Human CD20 Full Length, His Tag (CD0-H52H1) is expressed from human 293 cells (HEK293). It contains AA Met 1 - Pro 297 (Accession # P11836-1).
Predicted N-terminus: Met 1
Request for sequence
蛋白结构（Molecular Characterization）
The CD20 carries a polyhistidine tag at the C-terminus with calculated MW of 35.2 kDa and migrates as 40 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation. The membrane scaffold protein (MSP1D1) has calculated MW of 24.7 kDa, and it migrates as 25 kDa under reducing (R) condition (SDS-PAGE).
Nanodiscs are a new class of model membranes that are being used to solubilize and study a range of integral membrane proteins and membrane-associated proteins. The Nanodisc bilayer is bounded by a membrane scaffold protein (MSP1D1) coat that confers enhanced stability and a narrow particle size distribution.
The nanodisc assembles from a mixture of full length membrane protein in detergent, phospholipid micelles and membrane scaffold protein(MSP1D1) upon removal of the detergent.
内毒素（Endotoxin）
Less than 1.0 EU per μg by the LAL method.
纯度（Purity）
>85% as determined by SDS-PAGE.
制剂（Formulation）
Supplied as 0.2 μm filtered solution in 20 mM HEPES, 150 mM NaCl, pH7.5 with trehalose as protectant.
Contact us for customized product form or formulation.
运输（Shipping）
This product is supplied and shipped with dry ice, please inquire the shipping cost.
存储（Storage）
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
- The product MUST be stored at -70°C or lower upon receipt;
- -70°C for 6 months under sterile conditions.
电泳（SDS-PAGE）
Human CD20 Full Length, His Tag on SDS-PAGE under reducing (R) condition. The gel was stained with Coomassie Blue. The purity of the protein is greater than 85%.
活性（Bioactivity）-ELISA
Immobilized Rituximab at 2 μg/mL (100 μL/well) can bind Human CD20 Full Length, His Tag (Cat. No. CD0-H52H1) with a linear range of 1-63 ng/mL (QC tested).
Protocol
Immobilized Human CD20 Full Length, His Tag (Cat. No. CD0-H52H1) at 5 μg/mL (100 μL/well) can bind Biosimilar of Obinutuzumab with a linear range of 0.3-5 ng/mL (Routinely tested).
Protocol
活性（Bioactivity）-BLI
Loaded Rituximab on Protein A Biosensor, can bind with Human CD20 Full Length, His Tag (Cat. No. CD0-H52H1) an affinity constant of 12.9 nM as determined in BLI assay (ForteBio Octet Red96e) (Routinely tested).
Protocol
活性（Bioactivity）-FACS
2e5 of CD20-CAR-293 cells transfected with anti-CD20-scFv were stained with 100 μL of 3 μg/mL of Human CD20 / MS4A1 Full Length Protein, His Tag (Nanodisc) (HEK293)(Cat. No. CD0-H52H1) and negative control protein respectively, washed and then followed by PE anti-His antibody and analyzed with FACS (QC tested).
Protocol
背景（Background）
B-lymphocyte antigen CD20 is also known as B-lymphocyte surface antigen B1, Leukocyte surface antigen Leu-16, Membrane-spanning 4-domains subfamily A member 1 and MS4A1, is an activated-glycosylated phosphoprotein expressed on the surface of all B-cells beginning at the pro-B phase (CD45R+, CD117+) and progressively increasing in concentration until maturity. CD20 is expressed on all stages of B cell development except the first and last; it is present from late pro-B cells through memory cells, but not on either early pro-B cells or plasma blasts and plasma cells. It is found on B-cell lymphomas, hairy cell leukemia, B-cell chronic lymphocytic leukemia, and melanoma cancer stem cells. The protein has no known natural ligand and its function is to enable optimal B-cell immune response, specifically against T-independent antigens. It is suspected that it acts as a calcium channel in the cell membrane. CD20 / MS4A1 is the target of the monoclonal antibodies (mAb) rituximab, Ibritumomab tiuxetan, and tositumomab, which are all active agents in the treatment of all B cell lymphomas and leukemias. Defects in CD20 / MS4A1 are the cause of immunodeficiency common variable type 5 (CVID5); also called antibody deficiency due to CD20 defect. CVID5 is a primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen.
