A sensitive, high-volume, colorimetric assay for protein phosphatases

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Protein phosphatases regulate crucial cellular processes.
• Existing phosphatase assays are often costly, hazardous, or unsuitable for high-throughput screening.
• The CD45 protein tyrosine phosphatase (PTPase) is a key target for pharmaceutical research.

Purpose of the Study:

• To develop a sensitive, non-radioactive colorimetric assay for screening protein phosphatase inhibitors.
• To adapt the assay for high-throughput screening using 96-well microtiter plates and standard ELISA readers.
• To facilitate the identification of specific inhibitors for phosphatases, including CD45 PTPase.

Main Methods:

• Development of a colorimetric assay measuring released phosphate.
• Utilization of small volumes in 96-well microtiter plates.
• Assay validation using a standard ELISA plate reader and robotic compatibility.

Main Results:

• The assay demonstrated sensitivity down to 0.5 nmol of released phosphate.
• The method is suitable for robotic automation, allowing thousands of compounds to be screened daily.
• The assay is reagent-sparing, cost-effective, and uses non-radioactive, readily obtainable reagents.
• The assay has been successfully applied to various phosphatase classes.

Conclusions:

• A novel, sensitive, and cost-effective colorimetric assay for protein phosphatase inhibition screening has been established.
• This non-radioactive assay is suitable for high-throughput screening and facilitates the discovery of novel phosphatase inhibitors.
• The assay's adaptability and efficiency support pharmaceutical industry efforts in identifying therapeutic agents targeting phosphatases.