Recombinant Human Kit ligand (KITLG) is produced in a mammalian expression system and comes with a C-terminal 6xHis-tag for easier purification and detection. This partial protein covers amino acids 26-214 and appears to maintain high purity levels of over 95% based on SDS-PAGE analysis. The protein shows biological activity with an ED50 of 2-10 ng/ml in TF-1 cell proliferation assays. Endotoxin levels stay below 1.0 EU/µg, which likely minimizes interference in experimental work.
KITLG, commonly called stem cell factor, seems to play a central role in hematopoiesis by acting as a ligand for the c-Kit receptor. The protein is involved in key signaling pathways that may influence cell survival, proliferation, and differentiation—particularly in hematopoietic cells. Given these regulatory functions, KITLG has become an important target in stem cell biology and oncology research, potentially offering insights into how cells grow and develop.
Potential Applications
Note: The applications listed below are based on what we know about this protein's biological functions, published research, and experience from experts in the field. However, we haven't fully tested all of these applications ourselves yet. We'd recommend running some preliminary tests first to make sure they work for your specific research goals.
1. Cell Proliferation and Viability Assays
This recombinant KITLG is confirmed to be biologically active (ED₅₀ 2-10 ng/ml in TF-1 cells) and suitable for proliferation studies in KIT-expressing hematopoietic cells. However, researchers should validate its activity in primary human hematopoietic stem/progenitor cells to ensure physiological relevance beyond the TF-1 cell line. The mammalian expression ensures proper glycosylation, but the partial sequence (lacking the full extracellular domain) may affect some functional aspects compared to full-length KITLG.
2. KIT Receptor Binding and Signaling Studies
The biologically active KITLG is appropriate for receptor binding studies, but the C-terminal His-tag may cause minor steric interference with receptor dimerization or downstream signaling complex formation. While the mammalian glycosylation supports authentic interactions, researchers should include controls with tag-free KITLG for precise kinetic measurements. Signaling studies should validate that phosphorylation patterns (e.g., KIT, AKT, MAPK) match those induced by full-length KITLG.
3. Hematopoietic Stem Cell Research
The protein can be used for hematopoietic stem cell studies, but the soluble form (26-214aa) may not fully replicate membrane-bound KITLG's functions in stem cell niches. Researchers should validate that effects on stem cell maintenance and differentiation match those induced by stromal cell co-cultures expressing membrane-bound KITLG. The mammalian expression ensures physiological glycosylation patterns important for stem cell regulation.
4. Antibody Development and Validation
This mammalian-expressed KITLG serves as a good antigen, but antibodies generated against this partial sequence may have limited epitope coverage. Comprehensive validation should include testing against full-length KITLG to ensure recognition of all functional domains. The His-tag may induce tag-specific antibodies, so cleavage or tag-free controls are recommended for immunization.
5. Protein-Protein Interaction Studies
The His-tag facilitates pull-down assays, but may increase the risk of non-specific binding. The partial sequence might miss interactions dependent on the full-length protein. Researchers should use stringent controls (e.g., empty resin, tag-only controls) and validate novel interactions with full-length KITLG. The mammalian glycosylation ensures authentic interactions with glycosylation-dependent partners.
Final Recommendation & Action Plan
This mammalian-expressed human KITLG partial protein with a C-terminal His-tag is a valuable reagent with confirmed bioactivity, but researchers should account for its partial nature and tag. For immediate use, employ it in the 2-20 ng/ml range based on the ED₅₀, but validate dose-response in primary human hematopoietic cells. For binding and signaling studies, the mammalian glycosylation ensures authentic interactions, but consider tag cleavage or include tag-free controls for precise measurements. When studying hematopoietic stem cells, complement with membrane-bound KITLG systems to ensure physiological relevance. For antibody development, this protein is suitable for generating domain-specific reagents, but validated against full-length KITLG. For interaction studies, the His-tag is useful for purification but requires careful controls to minimize artifacts. Always validate key findings with full-length KITLG when studying complex biological functions, and consider that different hematopoietic cell types may exhibit varying sensitivity to soluble versus membrane-bound KITLG stimulation.
