重组人白介素-13（rHuIL-13）

Recombinant Human Interleukin 13

品名	rHuIL-13
规格	25μg
描述	重组人白介素-13是一个单链的非糖基化多肽链，含112个氨基酸残基，两对二硫键，分子量约为12.3KD。
来源：	大肠杆菌 (E. coli)。
分子量：	约为12.3kDa。
纯度：	≥ 97%。
内毒素含量：	<1EU/µg，鲎试剂法测定。
生物活性：	用TF-1细胞增殖的方法进行测定，比活性约为≥1×106IU/mg。
配方：	本品为无菌冻干粉，缓冲体系为PBS，pH7.4，0.1%HSA。
复溶	建议开盖前以10,000rpm离心30-60秒，或3,000rpm离心5分钟，再使用建议使用0.2ml无菌水复溶。
保存	冻干样品自生产之日起在-20℃到-70℃可以稳定保存36个月。 溶解以后，该细胞因子能在2-8℃的无菌条件下保存一个月，或在-20℃到-70℃的人工除霜的冰箱中保存三个月，而无明显活性损失。 避免反复冻融。

IL-13 is an immunoregulatory cytokine that plays a key role in the pathogenesis of allergic asthma and atopy. It is secreted by Th1 and Th2 CD4+ T cells, NK cells, visceral smooth muscle cells, eosinophils, mast cells, and basophils. IL-13 circulates as a monomer with two internal disulfide bonds that contribute to a bundled four αhelix configuration. Mature human IL-13 shares 57%, 59%, and 94% amino acid sequence identity with mouse, rat, and rhesus IL-13, respectively. Despite the low homology, it exhibits cross species activity between human, mouse, and rat. IL-13 has diverse activities on numerous cell types. On macrophages, IL-13 suppresses the production of proinflammatory cytokines and other cytotoxic substances. On B cells, IL-13 induces immunoglobulin class switching to IgE, up-regulates the expression of MHC class II, CD71, CD72, and CD23, and co-stimulates proliferation. IL-13 upregulates IL-6 while downregulating IL-1 and TNFα production by fibroblasts and endothelial cells. IL-13 binds with low affinity to IL13 Rα1, triggering IL-13 Rα1 association with IL4 Rα. This high affinity receptor complex also functions as the type 2 IL-4 receptor complex. Additionally, IL-13 binds with high affinity to IL-13 Rα2 which is expressed intracellularly, on the cell surface, and as a soluble molecule. IL-13Rα2 regulates the bioavailability of both IL-13 and IL-4 and is overexpressed in glioma and several bronchial pathologies. Compared to wild type IL-13, the atopy associated R110Q variant of IL-13 elicits increased responsiveness from eosinophils that express low levels of IL-13 Rα2.
仅供实验室使用。