Accurate Detection of PI3K Kinase Activity – UA-Glo® Kinase ADP Detection Kit (with Substrate PIP₂:3PS), Supporting Tumor-Targeted Drug Development

The phosphatidylinositol-3-kinase (PI3K) and its mediated PI3K/Akt/mTOR signaling pathway play a central regulatory role in cell growth, proliferation, metabolism, survival, and immune regulation. However, hyperactivation of this pathway has been closely associated with the development of various human malignancies, including prostate cancer, breast cancer, colorectal cancer, and others. Abnormalities in the PI3K/Akt/mTOR signaling axis are not only key drivers of malignant transformation, treatment resistance, and immune evasion but also a prominent focus in the field of targeted cancer therapy.

Among the PI3K kinase family, Class I PI3K is the most extensively studied. It phosphorylates phosphatidylinositol-4,5-bisphosphate (PIP₂) to generate phosphatidylinositol-3,4,5-trisphosphate (PIP₃), thereby initiating the downstream AKT/mTOR cascade signaling and promoting tumor initiation and progression.

Unlike traditional ATP depletion assays, the UA-Glo® Kinase ADP Detection Kit offers a core technical advantage by directly quantifying ADP, the product of kinase reactions. The kit employs a two-step process for highly sensitive ADP detection: first, an ATP removal reagent is added to terminate the kinase reaction and deplete residual ATP; then, an ADP detection reagent converts ADP into ATP, generating a bioluminescent signal proportional to ADP concentration via a luciferase/luciferin system. Research shows that product detection methods offer higher sensitivity and dynamic range than substrate depletion methods, delivering excellent signal-to-noise ratios even at low ATP conversion rates.

1. Exceptional Sensitivity and Robustness
The UA-Glo® Kinase ADP Detection Kit can quantify ADP as low as 0.25 pmol with an excellent signal-to-background ratio. It delivers reliable results even with low enzyme amounts and in high-density plate formats (96/384-well), making it ideal for high-throughput screening (HTS) applications.

2. Superior Substrate Compatibility—Optimized for Lipid Kinases
A key highlight of this product is the inclusion of a pre-validated Class I PI3K-specific substrate, PIP₂:3PS. This substrate consists of phosphatidylinositol-4,5-bisphosphate (PIP₂) mixed with carrier phospholipid phosphatidylserine (PS) at a 1:3 ratio, closely matching the recognition preferences of Class I PI3Ks. The inclusion of PIP₂:3PS eliminates the significant challenges researchers face in preparing and optimizing lipid substrates—lipids are insoluble in aqueous solutions and exist in unique membrane environments in vivo, making them a critical technical hurdle in lipid kinase assay development.

3. Broad Kinase Applicability
In addition to PI3K lipid kinases, this kit can detect nearly all ADP-producing enzymes, including protein kinases, ATPases, drug efflux proteins (e.g., MDR1-Pgp), helicases, topoisomerases, and heat shock proteins. The kinase reaction supports ATP concentrations up to 1 mM, allowing differentiation between ATP-competitive and non-competitive inhibitors by adjusting ATP levels.

4. Simplified Workflow
The UA-Glo® features a "add-and-read" workflow—no antibodies, radioactive labeling, or solid-phase separation steps are required. The highly standardized detection protocol is suitable for automation and large-scale screening.

As the PI3K/Akt/mTOR signaling pathway continues to solidify its central role in tumor biology and precision therapy, the development of next-generation PI3K inhibitors with improved selectivity, reduced toxicity, and the ability to overcome resistance has become a global focus in drug discovery. The UA-Glo® Kinase ADP Detection Kit (with PI3K Substrate PIP₂:3PS) provides a sensitive, reliable, and user-friendly solution with pre-optimized substrates, offering an ideal biochemical tool for PI3K inhibitor screening and mechanistic studies—facilitating innovation from target to drug.

Catalog No.	Product Name
UA079043	UA-Glo® Kinase ADP Assay with PI3K Substrate PIP₂:3PS
UA070101	UA-Glo® Kinase ADP Assay
UA079021	UA-Glo® Kinase ADP Max Assay Kit
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