Recombinant Human Non-receptor tyrosine-protein kinase TYK2 (TYK2) is produced in E. coli and spans amino acids 589-875 with a partial sequence length. The protein includes an N-terminal 6xHis-tag, which makes purification and detection more straightforward. SDS-PAGE analysis shows purity levels above 90%. This product is strictly for research purposes—it's not meant for therapeutic use. The manufacturing process appears designed to keep endotoxin contamination to minimal levels.
TYK2 belongs to the Janus kinase family and plays an important role in transmitting cytokine-mediated signals. It participates in several signaling pathways, particularly those connected to immune response and inflammation. Given its central position in these pathways, TYK2 has become a major research focus for scientists studying immune regulation mechanisms and exploring potential therapeutic targets for immune-related diseases.
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.
TYK2 is a complex multi-domain protein whose full activity and regulation depend on intricate interdomain interactions, particularly between its kinase domain (JH1) and the adjacent pseudokinase domain (JH2), which is not included in this construct (residues 589-875aa primarily cover JH1). The JH2 domain plays a critical autoinhibitory role by directly interacting with the kinase domain's N-lobe, regulating its catalytic activity. The absence of the JH2 domain in this recombinant fragment means it lacks this essential regulatory constraint, which may lead to improper folding, constitutive activity, or instability, as the kinase domain's conformation is naturally stabilized by its interaction with JH2. Furthermore, the E. coli system lacks eukaryotic chaperones and post-translational modification machinery, increasing the risk of misfolding or aggregation for a human kinase domain. The N-terminal His-tag, while useful for purification, could also potentially sterically interfere with the N-terminal region of the kinase domain. While the protein fragment contains the core kinase domain, its correct folding and bioactivity cannot be assumed due to the absence of the regulatory pseudokinase domain and the limitations of the E. coli expression system. Experimental validation is essential.
1. In Vitro Kinase Domain Structural Studies
This recombinant TYK2 fragment could be used for structural studies only if its folding is experimentally verified. The high purity and His-tag facilitate handling. However, the structure determined may not represent the native conformation of the kinase domain within the full-length TYK2 protein, as it lacks the stabilizing and constraining influence of the pseudokinase domain (JH2). In full-length TYK2, the JH2 domain interacts with the JH1 domain's N-lobe, influencing its conformation. Therefore, structural data from this isolated domain might reveal artifacts or an unregulated state not reflective of physiological conditions. Techniques like X-ray crystallography or NMR would require prior validation of folding homogeneity (e.g., via size-exclusion chromatography and circular dichroism).
2. Antibody Development and Validation
This protein fragment is suitable as an immunogen for generating antibodies targeting linear epitopes within the kinase domain, as antibody production often relies on amino acid sequences. The high purity reduces contamination risks. However, if the protein is misfolded, antibodies generated may not recognize conformational epitopes present on the correctly folded, full-length TYK2 protein in its native cellular context. This could limit their utility in applications like immunoprecipitation or immunofluorescence that depend on native structure recognition. The His-tag might also induce tag-specific antibodies.
3. Protein-Protein Interaction Studies
The His-tagged fragment can be used technically in pull-down assays to screen for interaction partners. However, the biological relevance of any identified interactions is highly questionable. In the full-length protein, the kinase domain's interaction interfaces are modulated by the pseudokinase domain and other regions. An isolated, potentially misfolded, or unregulated kinase domain might exhibit non-physiological binding (false positives) or fail to interact with genuine partners that require the full-length protein context (false negatives). Results would require rigorous validation using full-length TYK2 or cellular models.
4. Biochemical Characterization and Inhibitor Screening
This application is highly dependent on confirmed folding and bioactivity. The kinase domain's enzymatic activity is tightly regulated by the pseudokinase domain in the full-length protein. An isolated kinase domain fragment might display aberrant activity (e.g., constitutive or absent). Therefore, using it for inhibitor screening or kinetic studies without prior functional validation could yield misleading results about compound efficacy or mechanism of action. Activity must first be verified using a robust kinase assay with a known substrate before any biochemical characterization.
Final Recommendation & Action Plan
To ensure reliable and biologically relevant outcomes, it is strongly recommended to experimentally validate the protein's folding and bioactivity before proceeding with functional applications. The action plan should begin with biophysical characterization using size-exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) to assess oligomeric state and monodispersity, and circular dichroism (CD) spectroscopy to analyze secondary structure. This should be followed by a functional kinase activity assay using a known substrate (e.g., a STAT-derived peptide) and measuring ATP consumption or phosphate release to confirm specific catalytic activity. If validation confirms the fragment is properly folded and active, it can be used cautiously for structural studies or inhibitor screening, with the clear understanding that results may not fully represent the behavior of the full-length, autoinhibited TYK2 protein. If validation fails or activity is aberrant, its use should be restricted to applications less dependent on native conformation, such as linear-epitope antibody production.
