Interleukin-22 Binding Protein (IL-22BP, Cytokine Receptor Family (CRF) 2-10, CRF2-X, IL-22 RA2), Fc

Human IL-22BP/Fc Chimera Interleukin 22 binding protein (IL-22BP), also known as cytokine receptor family (CRF) 2-10, CRF2-X, and IL-22 RA2, is a secreted glycoprotein belonging to the type II cytokine receptor family. The IL-22BP gene has been localized to chromosome 6 near the gene for IFN-£^ R1. It encodes a precursor protein of 231 amino acid (aa) residues with a 21 aa putative signal peptide and five potential N-linked glycolsylation sites. IL-22BP lacks a transmembrane and cytoplasmic domain and is most closely related to the extracellular domains of IL-22R (CRF2-9) and IL-20R (CRF2-8), sharing 33% and 34% aa sequence identity, respectively. It also shares sequence homology with the extracellular domains of IL-10R (29%), IL-10 Rb (30%), the IFN receptors (23-25%) and tissue factor (26%). IL-22BP antagonizes IL-22 activity by specifically binding IL-22 with high affinity and blocking its interaction with the cell surface IL-22 receptor heteromeric complex composed IL-22R and IL-20R. IL-22BP is expressed in multiple tissues. The, highest levels of expression are found in breast, lungs and colon. Source: A DNA sequence encoding the signal peptide from human CD33 joined with the extracellular domain of human IL-22BP (Kotenko, S.V. et al., 2001, J. Immunol. 166:7096-7103) was fused to the Fc region of human IgG1 via a linker peptide. The chimeric protein was expressed in a mouse myeloma cell line, NS0. Human CD33 Signal peptide (Met 1-Ala 16) Human IL-22BP (Thr 22-Pro 231) IEGRMD Human IgG1 (Pro 100-Lys 330) N C , Molecular Mass: he recombinant mature human IL-22BP/Fc chimera is a disulfide-linked homodimeric protein. Based on N-terminal amino acid sequencing, the mature protein starts at Thr 22 and has a calculated molecular mass of 51.3kD. As a result of glycosylation, the recombinant monomer migrates as an approximately 75-80kD protein in SDS-PAGE under reducing conditions. Purity : > 90%, as determined by SDS-PAGE and visualized by silver stain. , Endotoxin: < 1.0 EU/ug of the cytokine as determined by the LAL method. Activity: Measured by its ability to bind rhIL-22. Immobilized rhIL-22BP/Fc at 10ug/ml (100ul/well) can bind rhIL-22 with a linear range of 12.5-0.8 ng/ml in a functional ELISA. , Form: Lyophilized from a 0.2um filtered solution in PBS. Reconstitution: It is recommended that sterile PBS be added to the vial to prepare a working stock solution of no less than 100ug/ml. The carrier-free protein should be used immediately upon reconstitution to avoid losses in activity due to non-specific binding to the inside surface of the vial. For long term storage as a dilute solution, a carrier protein (e.g. 0.1% HSA or BSA) should be added to the vial. , Storage: Lyophilized samples are stable for greater than six months at -20°C to -70°C. Upon reconstitution, this cytokine, in the presence of a carrier protein, should be stored under sterile conditions at -20°C to -70°C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.