描述:
CST公司在人293细胞中表达重组的人BAFF (hBAFF) Ala134-Leu285 (Accession #NP_006564)。重组的hBAFF蛋白不含有标签,未糖基化时其分子量据推算为15,489Da。DTT-还原和未还原的蛋白迁移时是作为一个16kDa 的多肽而迁移。重组hBAFF蛋白的N-末端AVQGP的序列通过测序得到。6 μg 还原 (+) 和 非还原的(-) 重组hBAFF通过SDS-PAGE检测,纯度大于98%,所有批次的纯度均高于98%。重组蛋白hBAFF的生物活性是同过小鼠脾脏B细胞增殖实验确定的。每个批次的ED50在0.5-2 ng/ml之间。
有载体: 每微克hBAFF蛋白溶解在包含10 mM DTT 和 20 μg BSA的PBS(pH 7.2)溶液中,通过 0.22 μm 滤膜并冻干,胱氨酸对生物活性不是必需的。
无载体:每微克hBAFF蛋白溶解在包含10 mM DTT 的PBS(pH 7.2)溶液中,通过 0.22 μm 滤膜并冻干,胱氨酸对生物活性不是必需的。
BAFF, TNF超家族的蛋白成员,是一个同源三聚体跨膜蛋白,经过剪切后可以形成可溶性的细胞因子(1)。BAFF 也能进一步的聚合形成60聚体结构(1)。BAFF在中性粒细胞、巨噬细胞、树突状细胞、活化的T细胞和上皮细胞中表达(1,2)。BAFF 在B细胞的发育、存活和激活中发挥了主要的作用(1,3,4)。BAFF结合到3个不同的受体上—BAFF-R、TACI 和 BCMA (1)。这些受体在B细胞及其谱系细胞的发育中具有不同的表达形式(1,2,4)。不像BAFF-R 和BCMA只结合到BAFF的三聚体形式上, TACI只能结合到细胞膜上或者BAFF更高级的结构上(1)。BAFF/ BAFF-R 的相互作用激活典型和非典型的NF-κB信号通路, PI3K/Akt 和 mTOR (2,4)。通过BAFF-R激活非典型的NF-κB信号通路受到TRAF3负调控(5)。研究表明BAFF水平的升高可能加剧许多自身免疫性疾病,这使得它成为治疗的理想靶标(2)。
原厂资料:
Source / Purification
Recombinant human BAFF (hBAFF) Ala134-Leu285 (Accession #NP_006564) was expressed in human 293 cells at Cell Signaling Technology.
Molecular Characterization
Recombinant hBAFF contains no "tags" and the nonglycosylated protein has a calculated MW of 15,489. DTT-reduced and non-reduced protein migrate as 16 kDa polypeptides. The expected amino-terminal AVQGP of recombinant hBAFF was verified by amino acid sequencing.
Purity
>98% as determined by SDS-PAGE of 6 μg reduced (+) and non-reduced (-) recombinant hBAFF. All lots are greater than 98% pure.
Bioactivity
The bioactivity of recombinant hBAFF was determined in a cell proliferation assay using mouse splenic B cells. The ED50 of each lot is between 0.5-2 ng/ml.
Endotoxin
Less than 0.01 ng endotoxin/1 μg hBAFF.
Formulation
With carrier: Lyophilized from a 0.22 μm filtered solution of PBS, pH 7.2 containing 10 mM DTT and 20 μg BSA per 1 μg hBAFF. Cystines are not required for bioactivity. Carrier free: Lyophilized from a 0.22 μm filtered solution of PBS, pH 7.2 containing 10 mM DTT. Cystines are not required for bioactivity.
Background
BAFF, a member of the TNF superfamily of proteins, is a homotrimeric transmembrane protein, which is cleaved to produce a soluble cytokine (1). BAFF may also further oligomerize into 60-mer structures (1). BAFF is expressed by neutrophils, macrophages, dendritic cells, activated T cells, and epithelial cells (1,2). BAFF plays a key role in B cell development, survival, and activation (1,3,4). BAFF binds to three distinct receptors, BAFF-R, TACI, and BCMA (1). These receptors are differentially expressed during B cell development and among B cell subsets (1,2,4). While BAFF-R and BCMA bind to the homotrimeric form of BAFF, TACI only binds to membrane bound or higher order BAFF structures (1). The BAFF/ BAFF-R interaction activates both canonical and non-canonical NF-κB pathways, PI3K/Akt, and mTOR (2,4). Activation of the noncanonical NF-κB pathway via BAFF-R is negatively regulated by TRAF3 (5). Elevated levels of BAFF may exacerbate many autoimmune disorders, making it an attractive therapeutic target (2).