Description
Our bioactive Interleukin-4 (IL-4) Human, P. pastoris Recombinant Protein is a single, glycosylated polypeptide chain that contains 129 amino acids. The IL-4 protein is recombinantly expressed in P. pastoris yeast and is purified by proprietary chromatographic techniques.
Summary
IL-4 is a cytokine secreted primarily by mast cells, T-cells, eosinophils, and basophils that plays a role in regulating antibody production, hematopoiesis and inflammation, and the development of effector T-cell responses. Induces the expression of class II MHC molecules on resting B-cells. Enhances both secretion and cell surface expression of IgE and IgG1. Also regulates the expression of the low affinity Fc receptor for IgE (CD23) on both lymphocytes and monocytes. Positively regulates IL31RA expression in macrophages. Stimulates autophagy in dendritic cells by interfering with mTORC1 signaling and through the induction of RUFY4. In addition, plays a critical role in higher functions of the normal brain, such as memory and learning. Upon binding to IL4, IL4R receptor dimerizes either with the common IL2R gamma chain/IL2RG to produce the type 1 signaling complex, located mainly on hematopoietic cells, or with the IL13RA1 to produce the type 2 complex, which is also expressed on nonhematopoietic cells. Engagement of both types of receptors initiates JAK3 and to a lower extend JAK1 phosphorylation leading to activation of the signal transducer and activator of transcription 6/STAT6.
Other Names
Interleukin 4, IL4, B-cell stimulatory factor 1 (BSF-1), Lymphocyte stimulatory factor 1, UniProtKB# P05112.
Source
Expressed in P. pastoris yeast.
Formulation
Sterile filtered white lyophilized (freeze-dried) powder. IL-4 protein was lyophilized from a 0.2 µm filtered solution in 20 mM sodium phosphate buffer pH 6.0 in absence of any carrier protein.
Purity
Greater than 98% as determined by SDS-PAGE analysis.
Biological Activity
The biological activity is determined by measuring the dose-dependent proliferation of human TF–1 cells and CD23 expression. A concentration range of 0.1–10.0 ng/ml is effective for most in vitro applications. ED50 = 0.05–0.4 ng/ml.
Reconstitution
It is recommended to reconstitute the lyophilized Interleukin-4 in sterile 18MΩ-cm H2O not less than 100 µg/ml, which can then be further diluted to other aqueous solutions.
Shipping
At ambient temperature. Upon receipt, store the product at the temperature recommended below.
Storage/Expiration
Lyophilized IL-4, although stable at room temperature for 3 weeks, should be stored desiccated below -18°C. Upon reconstitution, IL-4 should be stored at 4°C between 2-7 days and for future use below -18°C. Please prevent freeze-thaw cycles.
Usage
This product is intended for Laboratory Research Use Only. Not for use in diagnostic or therapeutic procedures. This product may not be used as a pharmaceutical or veterinary drug, agricultural product, or food additive.