This recombinant mouse Glutaminyl-peptide cyclotransferase (Qpct) is expressed in a yeast system, which appears to offer a reliable and efficient production method. The protein carries an N-terminal 6xHis-tag that helps with purification and detection. It includes the full length of the mature protein, spanning amino acids 36 to 362. The product shows purity levels exceeding 90%, as confirmed by SDS-PAGE analysis, which likely ensures high-quality results for research applications.
Glutaminyl-peptide cyclotransferase (Qpct) is an enzyme that participates in the post-translational modification of proteins. It plays what appears to be a critical role in converting glutaminyl residues into pyroglutamyl residues—a modification that seems important for protein stability and function. This enzyme may be relevant in various physiological pathways and has become a subject of interest for researchers studying protein processing and regulation.
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.
Based on the provided information, recombinant mouse Qpct is produced in a yeast expression system as the full-length mature protein (36-362aa) with an N-terminal 6xHis-Flag tag. Yeast expression systems provide eukaryotic folding machinery capable of supporting disulfide bond formation and some post-translational modifications, which are important for Qpct's enzymatic activity in catalyzing N-terminal glutaminyl cyclization. As a full-length protein expressed in a eukaryotic system, it has a high probability of correct folding. However, Qpct requires precise active site formation and may need proper metal cofactor incorporation for activity. The dual His-Flag tag at the N-terminus is relatively large and may potentially interfere with protein folding or function. No validation data (e.g., enzymatic activity assays, circular dichroism) are provided. Therefore, while yeast expression increases the probability of correct folding, the protein's enzymatic activity cannot be confirmed without experimental validation.
1. Biochemical Characterization and Enzyme Kinetics Studies
If the recombinant Qpct is correctly folded and functional, it can be used for enzyme kinetics studies to characterize substrate specificity and kinetic parameters. However, if inactive (due to improper folding, lack of cofactors, or tag interference), activity assays would yield invalid results. The His-Flag tag may sterically hinder the active site or substrate access even with correct folding.
2. Antibody Development and Validation
This application is suitable, as antibody generation primarily relies on linear epitope recognition. The full-length protein provides comprehensive epitope coverage. However, if misfolded, antibodies may not optimally recognize conformational epitopes of native Qpct in biological contexts.
3. Protein-Protein Interaction Studies
If properly folded, the His-tagged Qpct could be used in pull-down assays to identify interaction partners. However, if misfolded, interaction domains may be altered, leading to non-specific binding. The large dual tag may also cause steric hindrance in some interactions.
4. Structural and Biophysical Analysis
If correctly folded, the protein is suitable for structural studies, but the His-Flag tag should be removed for high-resolution structural determination (X-ray crystallography, NMR) as it may interfere with crystallization or analysis. For biophysical characterization, the tag may slightly alter hydrodynamic properties.
5. Comparative Species Studies and Evolutionary Analysis
If functionally active, the recombinant Qpct enables valid comparative studies with orthologs from other species. However, activity validation is essential first, as improper folding would make cross-species comparisons biologically meaningless.
Final Recommendation & Action Plan
This yeast-expressed full-length Qpct has a high probability of proper folding due to the eukaryotic expression system, but requires validation before functional applications. The recommended action plan includes: (1) Validate enzymatic activity using specific glutaminyl peptide substrates with appropriate controls; (2) Confirm proper folding through biophysical methods (circular dichroism for secondary structure, size-exclusion chromatography for oligomeric state); (3) For structural studies, consider removing the dual tag proteolytically for highest resolution analysis; (4) Antibody development can proceed immediately, but validate antibodies against native Qpct; (5) For comparative studies, ensure all compared proteins are similarly validated for activity. Always include positive controls (known active Qpct) in functional experiments. If validation confirms activity, proceed with applications while noting potential tag interference; if inactive, consider using tag-free protein or alternative expression systems.
