APC-Labeled Human CD19 (20-291) Protein, His Tag

分子別名（Synonym）

CD19, B4, CVID3, MGC12802

表達(dá)區(qū)間及表達(dá)系統(tǒng)（Source）

APC-Labeled Human CD19 (20-291), His Tag (CD9-HA2H9) is produced via conjugation of APC to Human CD19 (20-291), His Tag with a new generation site-specific technology under Star Staining labeling platform. Human CD19 (20-291), His Tag is expressed from human 293 cells (HEK293). It contains AA Pro 20 - Lys 291 (Accession # P15391-1).

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

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

偶聯(lián)（Conjugate）

APC

Excitation Wavelength: 640 nm

Emission Wavelength: 661 nm

制劑（Formulation）

Lyophilized from 0.22 μm filtered solution in PBS, 0.2% BSA, 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（Storage）

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

Please protect from light and 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（亦稱CD19或分化簇19）是一種單次跨膜I型膜蛋白，其胞外區(qū)含有兩個(gè)免疫球蛋白樣C2型結(jié)構(gòu)域。該蛋白表達(dá)于濾泡樹突細(xì)胞及B細(xì)胞表面，在B細(xì)胞發(fā)育全程——從最早可識別的B系祖細(xì)胞至B母細(xì)胞階段持續(xù)存在，但在成熟為漿細(xì)胞時(shí)消失。CD19主要作為B細(xì)胞共受體，與CD21及CD81協(xié)同發(fā)揮作用。

當(dāng)B細(xì)胞激活時(shí)，CD19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PI3激酶。與T細(xì)胞類似，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。CD19作為（近乎）B細(xì)胞特異性的磷酸化糖蛋白，與CD21、CD81共同組成該復(fù)合物。這些表面免疫球蛋白（sIg）關(guān)聯(lián)分子協(xié)同介導(dǎo)信號轉(zhuǎn)導(dǎo)。

在活體B細(xì)胞中，模擬外源抗原的抗免疫球蛋白抗體會引發(fā)CD19與sIg結(jié)合并隨之發(fā)生內(nèi)化。逆向過程尚未被證實(shí)，表明該受體復(fù)合物的形成由抗原誘導(dǎo)。此分子互作機(jī)制已通過化學(xué)研究獲得驗(yàn)證。CD19基因突變可導(dǎo)致以抗體生成缺陷為特征的重度免疫缺陷綜合征。研究證實(shí)CD19可與下列分子相互作用：CD81、CD82、補(bǔ)體受體2及VAV2。