Recombinant Human CD117/c-kit Protein Summary
| Description |
A biologically active protein corresponding to KIT.
Amino Acid Sequence: GSSQPSVSPGEPSPPSIHPGKSDLIVRVGDEIRLLCTDPGFVKWTFEILDETNENKQNEWITEKAEATNTGKYTCTNKHGLSNSIYVFVRDPAKLFLVDRSLYGKEDNDTLVRCPLTDPEVTNYSLKGCQGKPLPKDLRFIPDPKAGIMIKSVKRAYHRLCLHCSVDQEGKSVLSEKFILKVRPAFKAVPVVSVSKASYLLREGEEFTVTCTIKDVSSSVYSTWKRENSQTKLQEKYNSWHHGDFNYERQATLTISSARVNDSGVFMCYANNTFGSANVTTTLEVVDKGFINIFPMINTTVFVNDGENVDLIVEYEAFPKPEHQQWIYMNRTFTDKWEDYPKSENESNIRYVSELHLTRLKGTEGGTYTFLVSNSDVNAAIAFNVYVNTKPEILTYDRLVNGMLQCVAAGFPEPTIDWYFCPGTEQRCSASVLPVDVQTLNSSGPPFGKLVVQSSIDSSAFKHNGTVECKAYNDVGKTSAYFNFAFKGNNKEQIHPHTGSSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK |
| Preparation Method |
A DNA sequence encoding the signal peptide and extracellular domain of human SCF R (aa1-520) was fused to the Fc region of human IgG1 (aa 93-330). The chimeric protein wasexpressed in modified human 293 cells.
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| Details of Functionality |
The ED50 of the SCF R – Fc hcx Chimera typically 1-3 ug/ml as measured by its ability toneutralize SCF mediated proliferation using the human growth factor dependent M-07e cellline.
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| Protein/Peptide Type |
Biologically Active Protein
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| Gene |
KIT
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Applications/Dilutions
| Application Notes |
SCF R – Fc hcx Chimera separates into a number of isoforms with a pI between4.5 and 8 in 2D PAGE due to post-translational modifications, in particular glycosylation.This compares with the unmodified SCF R – Fc Chimera that has a predicted pI of 6.6. SCF R – Fc hcx Chimera migrates as a broad band between 90 and 150 kDa in SDS-PAGE due to post-translational modifications, in particular glycosylation. This compares with the unmodified SCF R – Fc Chimera that has a predicted molecular mass of 83.1 kDa. SCF R – Fc hcx Chimera is N- and O-glycosylated.
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Reactivity Notes
This is a Human protein
Packaging, Storage & Formulations
| Storage |
Store at -80C. Avoid freeze-thaw cycles.
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| Concentration |
LYOPH
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| Reconstitution Instructions |
Reconstitute with 0.5 ml sterilized PBS containing 1% human serum albumin and 10% trehalose.
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Alternate Names for Recombinant Human CD117/c-kit Protein
- CD117 antigen
- CD117
- ckit
- c-kit
- EC 2.7.10
- EC 2.7.10.1
- KIT
- PBT
- piebald trait
- Proto-oncogene c-Kit
- proto-oncogene tyrosine-protein kinase Kit
- SCF R
- SCFRmast/stem cell growth factor receptor
- soluble KIT variant 1
- Tyrosine-protein kinase Kit
- v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog
- v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene-like protein
Background
Stem cell factor receptor (SCF R), also known as c-kit, has a molecular weight of 145 kDa as a mature protein and is a member of the type III receptor tyrosine kinase (RTK) family that includes platelet-derived growth factor (PDGF) receptors and the macrophage colony-stimulating factor 1 (CSF-1) (c-fms) receptor. SCF R is essential for the development of normal hematopoietic cells and plays an important role in the survival, proliferation, and differentiation of mast cells, melanocytes, and germ cells. It is expressed by hematopoietic cells in the embryonic liver throughout development, and by more committed progenitors, such as myeloid, erythroid, megakaryocytic, natural killer, and dendritic progenitor cells. SCF R contains five extracellular immunoglobulin-like (Ig) domains, a single juxtamembrane domain (JMD), a cytoplasmic tyrosine kinase domain interrupted by a large kinase insert (KI) in the ATP-binging region, and a carboxy tail. Binding of SCF R to its ligand (stem cell factor; SCF) induces receptor dimerization, trans autophosphorylation of the kinase domain, recruitment of signaling proteins via phosphotyrosine binding or Src homology 2 (SH2) domains, and subsequent signal transduction. A variety of human diseases are associated with the inappropriate expression or activation of SCF R, which can be classified as loss-of-function mutations or gain-of-function mutations. Activating mutations in SCF R have been primarily identified in the JMD and in the second part of the kinase domain, and are associated with gastrointestinal stromal cell tumors and mastocytosis, respectively. There are also reports of activating mutations in some forms of germ cell tumors. The overexpression of SCF R has previously been documented in myeloid leukemia, neuroblastoma, breast tumor, colon tumors, gynecological tumors, testicular germ cell tumors and small cell lung carcinoma (SCLC). Loss-of-function mutations in SCF R can result in diseases such as autosomal-dominant piebaldism, leading to deafness, megacolon, and abnormalities in pigmentation of skin and hair. This is a HCX protein. HCX Expression System Details HCX proteins mimic the proteins in the human body because they are expressed from human, rather than animal, insect or bacterial cells. This process gives them human post-translational modifications. Recombinant DNA techniques allow a human protein with the correct amino acid sequence to be expressed in a non-human cell line. However, non-human cells lack the appropriate cellular machinery, such as specific glycosyltransferases, necessary to produce the correct human post-translational modifications of a protein. An extreme example is seen in E. coli cells, which produce recombinant proteins with no glycosylation, as the above figure illustrates. Rodent and yeast cells are able to glycosylate proteins, but they are still different from glycosylation in human cells. Expression System Resultant Proteins Human (e.g. K562, HEK293) Correct amino acid sequence Human post-translational modifications Rodent (e.g. CHO, NSO) Correct amino acid sequence Some natural glycosylation – not human-like Yeast (e.g. Pichia) Correct amino acid sequence Some natural glycosylation – not human-like E.Coli Correct amino acid sequence No PTMs Although there have been significant attempts to make non-human cell derived cytokines more human-like, there is a growing awareness that in many instances, particularly in therapeutics, cytokines should mimic those found in the body as closely as possible.Purified SCF R – Fc hcx Chimera consists of 5-45% carbohydrate by weight.