Overview of Recombinant Human ILK Protein

Integrin-linked kinase (ILK) is a serine/threonine protein kinase that plays a central role in the signaling pathways downstream of integrins and growth factor receptors. ILK interacts with the cytoplasmic tails of β1 and β3 integrins and serves as a scaffold for multi-protein complexes that regulate cell adhesion, spreading, migration, and survival.

Recombinant Human ILK Protein (SKU: rp370802) is produced to support researchers studying integrin-mediated signaling, focal adhesion dynamics, and the phosphorylation of downstream substrates such as AKT (Ser473) and GSK-3β (Ser9). This recombinant protein is suitable for use in biochemical assays, pull-down experiments, and structural studies.

Materials and Reagents

Before beginning the protocol, ensure the following materials are available:

• Recombinant Human ILK Protein (rp370802, Aladdin Scientific)
• Sterile deionized water or phosphate-buffered saline (PBS, pH 7.4)
• Kinase assay buffer (e.g., 25 mM HEPES pH 7.5, 10 mM MgCl₂, 1 mM DTT, 0.01% Tween-20)
• ATP solution (prepared fresh; typical working concentration 100 µM)
• Appropriate peptide or protein substrate (e.g., myelin basic protein or a synthetic AKT substrate peptide)
• Microcentrifuge and low-binding microcentrifuge tubes
• Ice and dry ice for cold-chain maintenance
• BSA (for protein normalization and blocking steps)
• SDS-PAGE and Western blot reagents (for downstream verification, if required)

Note: All specific buffer compositions, substrate concentrations, and ATP amounts should be verified against the product datasheet provided with the lot and adjusted empirically for each experimental system.

Step-by-Step Protocol: Reconstitution, Storage, and Kinase Activity Assay

Step 1: Reconstitution

1. Remove the vial from -80°C storage and allow it to equilibrate briefly on ice.
2. Briefly centrifuge the vial (e.g., 5–10 seconds at low speed) to collect lyophilized material at the bottom.
3. Add the volume of sterile deionized water or reconstitution buffer specified on the product datasheet to achieve the desired stock concentration.
4. Gently pipette up and down to dissolve; do not vortex vigorously, as this may denature the protein.
5. Allow the solution to stand on ice for 5–10 minutes, then briefly centrifuge again to remove any insoluble material.

Step 2: Aliquoting and Storage

1. Divide the reconstituted protein into single-use aliquots to avoid repeated freeze-thaw cycles.
2. Store aliquots at -80°C for long-term use or at -20°C for short-term use (up to 1 month). Refer to the product datasheet for lot-specific stability data.
3. Add a carrier protein (e.g., 0.1% BSA) if diluting to very low concentrations to prevent adsorption to tube walls.

Step 3: In Vitro Kinase Activity Assay

1. Prepare the kinase reaction mixture on ice: combine kinase assay buffer, ATP (freshly prepared), peptide/protein substrate, and Recombinant Human ILK Protein at appropriate concentrations per the datasheet.
2. Initiate the reaction by transferring tubes to 30°C and incubate for the recommended time period (typically 30–60 minutes; verify with datasheet).
3. Terminate the reaction by adding SDS loading buffer (for gel-based readout) or stop solution per the chosen detection method.
4. Analyze phosphorylation of the substrate by SDS-PAGE followed by Western blotting using a phospho-specific antibody, or by radioactive or fluorescence-based kinase assay kits.

Step 4: Controls

• Include a no-enzyme negative control (buffer only + substrate + ATP) to assess background phosphorylation.
• Include a kinase inhibitor control if evaluating inhibitor compounds.
• Use a well-characterized positive control kinase reaction when available.

Troubleshooting and Quality Considerations

The following troubleshooting guidance addresses common issues encountered when working with Recombinant Human ILK Protein:

Always consult the lot-specific Certificate of Analysis (CoA) for purity, concentration, and activity data before initiating experiments.

Safety, Disposal, and Regulatory Notes

Recombinant Human ILK Protein is intended for research use only (RUO) and is not approved for diagnostic or therapeutic applications in humans or animals.

Safety: Handle recombinant proteins with standard laboratory precautions. Wear appropriate personal protective equipment (PPE) including gloves, lab coat, and eye protection. Although this protein is not classified as a biohazard, it is derived from human gene sequences; follow institutional biosafety guidelines.

Disposal: Dispose of protein solutions and contaminated materials in accordance with applicable local, national, and institutional regulations for biological waste.

Regulatory: This product is for in vitro laboratory research use only. It has not been evaluated by any regulatory agency for safety or efficacy in clinical applications. Procurement and use should comply with all relevant institutional review and import/export regulations.