Recombinant Human GKN1 Protein: Properties & Research Guide

Recombinant Human GKN1 Protein is a research-grade gastric mucosal protein that plays a critical role in maintaining gastric epithelial homeostasis and has emerged as a significant subject of study in gastric cancer biology.

Product Name

Recombinant Human GKN1 Protein

SKU

rp367957

Protein Origin

Human (Homo sapiens)

Protein Type

Recombinant, research grade

Primary Function

Gastric mucosal protection and epithelial homeostasis

Research Relevance

Implicated in gastric cancer suppression and H. pylori-associated pathology

What Is GKN1 and Why Does It Matter?

Gastrokine 1 (GKN1) is a secreted protein expressed predominantly in the surface mucous cells of the gastric antrum and body. It is a member of the Gastrokine family, characterized by a conserved BRICHOS domain that is associated with protein folding and mucosal protection. GKN1 is considered a gastric-specific protein and plays an essential role in maintaining the integrity of the gastric epithelium.

A defining feature of GKN1 is its marked downregulation or complete loss of expression in gastric cancer tissues and in cells infected with Helicobacter pylori. This pattern of expression loss has led researchers to classify GKN1 as a candidate gastric tumor suppressor. Its ability to induce apoptosis, inhibit cell proliferation, and promote epithelial differentiation makes it a subject of intense investigation in the context of gastric carcinogenesis and mucosal repair.

Recombinant Human GKN1 Protein produced under controlled conditions enables researchers to study these functions in vitro and in vivo without reliance on limited endogenous tissue sources, providing a reproducible and well-defined tool for mechanistic and translational studies.

Recommended Handling and Storage Protocol

Proper handling of Recombinant Human GKN1 Protein is essential to preserve its biological activity and structural integrity. The following general guidelines are recommended for research use:

• Reconstitution: If supplied in lyophilized form, reconstitute the protein in sterile, deionized water or an appropriate buffer (e.g., PBS, pH 7.4) to the desired concentration. Allow the vial to equilibrate to room temperature before opening, and centrifuge briefly before reconstitution to pellet any material at the vial cap.
• Storage: Store lyophilized protein at −20 °C or −80 °C upon receipt. Once reconstituted, aliquot to avoid repeated freeze-thaw cycles and store aliquots at −80 °C. Refer to the specific product datasheet for confirmed storage conditions for SKU rp367957.
• Working Concentration: Optimal working concentrations should be determined empirically for each assay system. Start with concentrations typically used in the literature for GKN1 functional studies and titrate as needed.
• Carrier Protein: For long-term stability of dilute solutions, consider adding a carrier protein such as 0.1% BSA. Confirm compatibility with your downstream assay before use.
• Avoid Repeated Freeze-Thaw: Repeated freeze-thaw cycles can denature the protein and reduce biological activity. Prepare single-use aliquots at the time of reconstitution.

Always consult the product-specific datasheet provided with SKU rp367957 for exact buffer composition, concentration, and verified storage conditions, as these supersede general guidelines.

Research Applications of Recombinant Human GKN1 Protein

Recombinant Human GKN1 Protein is a versatile reagent suited to a range of in vitro and in vivo experimental workflows. Key applications include:

• Cell Proliferation and Apoptosis Assays: GKN1 has been reported to suppress proliferation and induce apoptosis in gastric cancer cell lines. Recombinant GKN1 can be used to treat gastric cancer cells (e.g., AGS, MKN-45) and assess changes in cell viability, caspase activation, and cell cycle distribution.
• Epithelial Differentiation Studies: Use recombinant GKN1 to investigate its role in promoting differentiation of gastric epithelial cells and restoring normal mucosal phenotype in disease models.
• Protein–Protein Interaction Studies: GKN1 interacts with trefoil factor 1 (TFF1) and other mucosal proteins. Recombinant protein preparations are useful for co-immunoprecipitation, pull-down assays, and surface plasmon resonance studies to map these interactions.
• Biomarker Validation: Recombinant GKN1 serves as a positive control antigen in ELISA, Western blot, and immunohistochemistry assays designed to detect and quantify GKN1 expression in clinical or experimental samples.
• H. pylori Infection Models: Recombinant GKN1 can be used to study the molecular mechanisms by which H. pylori suppresses GKN1 expression and the downstream effects on epithelial integrity.
• Functional Rescue Experiments: In GKN1-deficient cell or animal models, recombinant protein can be applied to determine whether exogenous GKN1 rescues normal cellular behavior, supporting loss-of-function studies.

Quality Considerations and Experimental Best Practices

To obtain reliable and reproducible results with Recombinant Human GKN1 Protein, researchers should consider the following quality and experimental factors:

• Purity Verification: Confirm protein purity by SDS-PAGE or HPLC analysis. High-purity preparations minimize interference from contaminant proteins in functional assays. Check the Certificate of Analysis (CoA) for SKU rp367957 for lot-specific purity data.
• Endotoxin Testing: For cell-based and in vivo assays, endotoxin levels must be sufficiently low to avoid confounding inflammatory responses. Verify endotoxin content from the CoA; if not specified, request endotoxin testing data from Aladdin Scientific.
• Biological Activity Confirmation: Where possible, validate biological activity using a functional assay (e.g., cell proliferation inhibition assay) before committing large volumes to a study. Include appropriate positive and negative controls.
• Lot-to-Lot Consistency: When designing longitudinal studies or multi-cohort experiments, purchase sufficient material from a single lot to minimize inter-lot variability. Document the lot number in all experimental records.
• Buffer Compatibility: Ensure the formulation buffer of the recombinant protein is compatible with your assay system. Dialyze or buffer-exchange if necessary, noting that this step may affect protein concentration and activity.

Frequently asked questions

What is the biological function of GKN1 in the gastric mucosa?

GKN1 (Gastrokine 1) is a secreted protein that maintains gastric epithelial homeostasis by promoting mucosal cell differentiation, suppressing abnormal proliferation, and facilitating apoptosis of damaged cells. It is specifically expressed in the stomach and is considered a tumor suppressor due to its consistent downregulation in gastric cancer and H. pylori infection contexts.

How should Recombinant Human GKN1 Protein be stored to maintain activity?

Lyophilized Recombinant Human GKN1 Protein should be stored at −20 °C or −80 °C. After reconstitution, the protein should be aliquoted into single-use volumes and stored at −80 °C to avoid repeated freeze-thaw cycles, which can degrade protein structure and reduce biological activity. Always consult the product-specific datasheet for SKU rp367957 for confirmed storage recommendations.

Can Recombinant Human GKN1 Protein be used as a Western blot positive control?

Yes. Recombinant Human GKN1 Protein is well-suited for use as a positive control antigen in Western blot, ELISA, and immunohistochemistry assays. Using a defined recombinant protein ensures a consistent, quantifiable signal and helps validate antibody specificity and assay performance across experimental runs.

Is endotoxin content a concern when using recombinant GKN1 in cell-based assays?

Yes, endotoxin contamination is an important consideration for any recombinant protein used in cell-based or in vivo assays, as even low levels can trigger inflammatory responses that confound experimental results. Researchers should verify the endotoxin content listed on the Certificate of Analysis for SKU rp367957 and confirm it meets the threshold required for their specific assay system.

What cell lines are commonly used to study GKN1 function with recombinant protein?

Gastric cancer cell lines such as AGS and MKN-45, which have reduced or absent endogenous GKN1 expression, are commonly used in GKN1 functional studies. Treatment with exogenous recombinant GKN1 in these cells allows researchers to evaluate effects on proliferation, apoptosis, and differentiation in a controlled setting.

References

1. Nardone G, et al. Molecular basis of gastric cancer development and progression. Gastroenterology. 2007.
2. Yoon JH, et al. Gastrokine 1 functions as a tumor suppressor in gastric cancers. Clinical Cancer Research. 2011.
3. Aladdin Scientific. Product Datasheet: Recombinant Human GKN1 Protein, SKU rp367957. Aladdin Scientific.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.