Biotinylated Human CD19 Protein, Fc Tag, ultra sensitivity (primary amine labeling)

分子別名（Synonym）

CD19,B4,CVID3,MGC12802

表達(dá)區(qū)間及表達(dá)系統(tǒng)（Source）

Biotinylated Human CD19 Protein, Fc Tag, primary amine labeling (CD9-H8259) is expressed from human 293 cells (HEK293). It contains AA Pro 20 - Lys 291 (Accession # P15391-1).

Predicted N-terminus: Pro 20

蛋白結(jié)構(gòu)（Molecular Characterization）

This protein carries a human IgG1 Fc tag at the C-terminus.

The protein has a calculated MW of 56.3 kDa. The protein migrates as 60-80 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

標(biāo)記（Labeling）

The primary amines in the side chains of lysine residues and the N-terminus of the protein are conjugated with biotins using standard chemical labeling method. A standard biotin reagent (13.5 angstroms) is used in this product.

蛋白標(biāo)記度（Protein Ratio）

Passed as determined by the HABA assay / binding ELISA.

純度（Purity）

>95% as determined by SDS-PAGE.

制劑（Formulation）

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

Contact us for customized product form or formulation.

重構(gòu)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.

存儲(chǔ)（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.

背景介紹

B淋巴細(xì)胞抗原CD19（又稱(chēng)分化簇19），是一種單次跨膜的I型膜蛋白，其結(jié)構(gòu)中含有兩個(gè)免疫球蛋白樣C2型結(jié)構(gòu)域。該蛋白在濾泡樹(shù)突細(xì)胞與B細(xì)胞表面表達(dá)，實(shí)際上從發(fā)育過(guò)程中最早可識(shí)別的B系細(xì)胞到B母細(xì)胞階段均持續(xù)存在，但在分化為漿細(xì)胞時(shí)丟失。CD19主要作為B細(xì)胞共受體，與CD21和CD81協(xié)同發(fā)揮作用。當(dāng)被激活時(shí)，CD19的胞質(zhì)尾部發(fā)生磷酸化，進(jìn)而招募Src家族激酶并結(jié)合PI-3激酶。

與T細(xì)胞類(lèi)似，B淋巴細(xì)胞表面多個(gè)分子共同構(gòu)成抗原受體復(fù)合物。這種（近乎）B細(xì)胞特異性的CD19磷酸化糖蛋白即為關(guān)鍵組分之一，其他成分還包括CD21與CD81。這些表面免疫球蛋白相關(guān)分子共同參與信號(hào)轉(zhuǎn)導(dǎo)過(guò)程。在活體B細(xì)胞中，模擬外源抗原的抗免疫球蛋白抗體會(huì)引發(fā)CD19與表面免疫球蛋白結(jié)合并隨之內(nèi)化。反向過(guò)程尚未被證實(shí)，提示該受體復(fù)合物的形成由抗原誘導(dǎo)。這種分子相互作用已通過(guò)化學(xué)研究得到證實(shí)。

CD19基因突變會(huì)導(dǎo)致以抗體產(chǎn)生缺陷為特征的嚴(yán)重免疫缺陷綜合征。研究證實(shí)CD19可與多種蛋白發(fā)生相互作用，包括：CD81、CD82、補(bǔ)體受體2以及VAV2蛋白。