Recombinant Human Fibroblast Growth Factor 23 (FGF23) protein is expressed in E. coli, covering the full mature protein length from amino acids 25 to 251. This product is tag-free, which appears to help maintain the native structure. Purity exceeds 95% as confirmed by SDS-PAGE, and endotoxin levels remain below 1.0 EU/μg as determined by the LAL method. The protein shows full biological activity, with an ED50 of less than 0.5 μg/ml in thymidine uptake assays, suggesting a specific activity of more than 2.0 × 10³ IU/mg.
Fibroblast Growth Factor 23 (FGF23) serves as a critical regulator of phosphate and vitamin D metabolism. It plays what seems to be an essential role in maintaining phosphate homeostasis and is involved in regulating bone mineralization. FGF23 is mainly produced by osteocytes and osteoblasts. When its regulation goes awry, this can lead to disorders in mineral metabolism. This protein has become of significant interest in research focusing on metabolic bone diseases and related pathways.
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. FGF Receptor Binding and Signaling Studies
This recombinant FGF23 protein can be used to investigate the binding kinetics and signaling pathways of FGF receptors in vitro. The demonstrated biological activity through thymidine uptake assays in FGF-receptor transfected BaF3 cells confirms its functional interaction with FGF receptors. Researchers can use this protein to study dose-response relationships, receptor specificity, and downstream signaling cascades in various cell culture systems. The high purity and defined specific activity make it suitable for quantitative receptor-ligand interaction studies.
2. Klotho Co-factor Dependency Research
The activity testing method indicates that this FGF23 protein requires Klotho as a co-factor for optimal biological activity, making it valuable for studying FGF23-Klotho interactions. Researchers can use this protein to investigate the molecular mechanisms of how Klotho enhances FGF23 signaling and to determine optimal co-factor ratios for maximal activity. This application may be particularly relevant for understanding the biochemical requirements of FGF23 function and for developing in vitro assays that accurately recapitulate physiological conditions.
3. Cell Proliferation and Metabolic Assays
Given the established thymidine uptake activity in BaF3 cells, this FGF23 protein can serve as a positive control or test reagent in cell proliferation assays. The defined ED50 value provides a reference point for designing dose-response experiments in various cell lines expressing FGF receptors. Researchers can use this protein to study cellular metabolic responses, growth factor signaling pathways, and to validate new assay systems for FGF23 biological activity measurement.
4. Heparin-Dependent Signaling Mechanism Studies
The requirement for heparin in the activity testing protocol suggests this FGF23 protein can be used to investigate heparin-dependent signaling mechanisms. Researchers can study how different concentrations and types of heparin or heparan sulfate affect FGF23 biological activity and receptor binding. This application enables investigation of the role of glycosaminoglycans in FGF23 function. It may also help elucidate the molecular basis of FGF23 signaling complex formation.
5. Antibody Development and Validation
The high purity and biological activity of this recombinant FGF23 protein make it suitable for generating and validating antibodies against human FGF23. Researchers can use this protein as an immunogen for antibody production or as a standard for testing antibody specificity and binding affinity. The low endotoxin level appears to ensure minimal interference in immunological assays, while the confirmed biological activity allows for functional validation of neutralizing antibodies through the established thymidine uptake assay system.
