Monitoring Inositol-Specific Phospholipase C Activity Using a Phospholipid FlashPlate(R).

Area of Science:

• Biochemistry and enzymology
• Cell signaling and molecular biology
• Drug discovery and high-throughput screening (HTS)

Background:

• Inositol-specific phospholipase Cs (PLCs) are crucial enzymes in signal transduction pathways initiated by plasma membrane receptors.
• Accurate and efficient methods are needed to monitor PLC activity for understanding cellular processes and for drug screening.

Purpose of the Study:

• To develop and validate a modified solid-surface assay for monitoring phospholipase C (PLC) activity.
• To assess the utility of [(3)H] PIP(2)-Coated Phospholipid FlashPlate microtiter plates for high-throughput screening (HTS) of receptor-coupled functional assays.

Main Methods:

• Development of a modified solid surface to immobilize [(3)H] PIP(2) on Basic FlashPlate® microtiter plates.
• Assay validation using purified recombinant enzyme, HL60 cell lysates, and permeabilized A431 human carcinoma cells.
• Comparison of the solid-surface assay with classical solution-based radiolabeled mixed phospholipid micelle studies.

Main Results:

• The [(3)H] PIP(2)-Coated Phospholipid FlashPlate assay effectively captured and measured PLC activity.
• PLC activity was readily quantifiable from diverse sources, including purified enzymes and complex cellular lysates.
• The assay format demonstrated comparability to traditional solution-based methods, highlighting its robustness.

Conclusions:

• The [(3)H] PIP(2)-Coated Phospholipid FlashPlate assay is a valuable tool for assessing PLC activity in HTS campaigns.
• This method facilitates the measurement of PLC activation across various drug screening assays, offering a practical and efficient approach.
• The assay's versatility supports its application in diverse research settings for studying receptor-mediated signaling events.