人CD20 / MS4A1蛋白, His, Avitag

Biotinylated Human CD20 / MS4A1 Full Length Protein, His,Avitag™ (Nanodisc)

分子别名（Synonym）

MS4A1, CD20, MS4A-1

表达区间及表达系统（Source）

Biotinylated Human CD20 Full Length, His,Avitag (CD0-H82E3) is expressed from human 293 cells (HEK293). It contains AA Met 1 - Pro 297 (Accession # P11836-1).

Predicted N-terminus: Met 1

蛋白结构（Molecular Characterization）

The CD20 carries a polyhistidine tag at the C-terminus followed by an Avi tag with calculated MW of 36.9 kDa and migrates as 43 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

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 an amphipathic scaffold 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 upon removal of the detergent.

标记（Labeling）

Biotinylation of this product is performed using Avitag™ technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.

蛋白标记度（Protein Ratio）

Passed as determined by the HABA assay / binding ELISA.

纯度（Purity）

>90% 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 3 months under sterile conditions.

背景介绍

B淋巴细胞抗原CD20（亦称B淋巴细胞表面抗原B1、白细胞表面抗原Leu-16、跨膜4结构域亚家族A成员1，基因编号MS4A1）是一种活化糖基化磷蛋白。该蛋白从前B细胞阶段（CD45R+、CD117+）开始表达于所有B细胞表面，其浓度随细胞成熟度逐步递增。CD20存在于B细胞发育全过程（除最早期的前B细胞和最末期的浆母细胞/浆细胞阶段），从晚期前B细胞持续表达至记忆B细胞阶段。该蛋白在B细胞淋巴瘤、毛细胞白血病、B细胞慢性淋巴细胞白血病及黑色素瘤干细胞中均有表达。

CD20目前未发现天然配体，其功能是通过促进钙离子跨膜流动来增强B细胞免疫应答（尤其针对非T细胞依赖性抗原）。现有研究表明该蛋白可能作为钙离子通道发挥作用。CD20/MS4A1是单克隆抗体（包括利妥昔单抗、替伊莫单抗、托西莫单抗）的作用靶点，这些抗体药物被广泛应用于所有类型B细胞淋巴瘤和白血病的临床治疗。

CD20/MS4A1基因缺陷会导致常见变异型免疫缺陷病5型（CVID5，又称CD20缺陷性抗体缺乏症）。该原发性免疫缺陷病以抗体缺陷、低丙种球蛋白血症、反复细菌感染及抗原抗体应答缺失为主要特征。