小鼠CD19蛋白, His Tag

Mouse CD19 Protein, His Tag

分子别名（Synonym）

CD19, B4, CVID3, MGC12802

表达区间及表达系统（Source） 

Mouse CD19, His Tag (CD9-M52H8) is expressed from human 293 cells (HEK293). It contains AA Arg 19 - Gly 287 (Accession # P25918).

蛋白结构（Molecular Characterization）

This protein carries a polyhistidine tag at the C-terminus.

The protein has a calculated MW of 31.6 kDa. The protein migrates as 45-55 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

内毒素（Endotoxin）

Less than 1.0 EU per μg by the LAL method / rFC method.

纯度（Purity）

>90% as determined by SDS-PAGE.

制剂（Formulation）

Lyophilized from 0.22 μm filtered solution in PBS, pH7.4 with trehalose as protectant.

Contact us for customized product form or formulation.

重构方法（Reconstitution）

Please see Certificate of Analysis for specific instructions.

For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

存储（Storage）

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

This product is stable after storage at:

-20°C to -70°C for 12 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

背景介绍

B淋巴细胞抗原CD19（亦称为分化簇CD19），是一种I型单次跨膜蛋白，包含两个免疫球蛋白样C2型结构域。该蛋白在滤泡树突状细胞与B细胞表面表达，实际上从发育过程中最早可识别的B系细胞到B母细胞阶段持续存在，但在成熟分化为浆细胞时消失。其主要作为B细胞共受体与CD21、CD81协同作用：当激活时，CD19的胞质尾段发生磷酸化，进而介导Src家族激酶结合并招募PI-3激酶。与T细胞类似，B淋巴细胞表面多个分子共同构成抗原受体复合体，其中（近乎）B细胞特异性的CD19磷酸糖蛋白是关键组分之一（另包括CD21与CD81），这些表面免疫球蛋白关联分子共同促进信号转导。在活体B细胞中，模拟外源抗原的抗免疫球蛋白抗体会引发CD19与表面免疫球蛋白结合并随之内化，而反向过程尚未证实，提示该受体复合体的形成具有抗原诱导特性。此类分子相互作用已通过化学研究获得证实。CD19基因突变会导致以抗体产生缺陷为特征的严重免疫缺陷综合征。研究显示CD19可与CD81、CD82、补体受体2及VAV2等蛋白发生相互作用。