Transcreener(R) GDP FP Assay

The Transcreener(R) HTS Assay platform overcomes the need for time-consuming, one-off assay development for individual members within a group transfer enzyme family by utilizing a single set of assay reagents that detect an invariant product. The generic nature of the Transcreener HTS Assay platform eliminates delays involved in assay development for new HTS targets, and greatly simplifies compound and inhibitor profiling across multiple target families. The Transcreener GDP Assay is a far-red, competitive fluorescence polarization (FP) assay based on the detection of GDP and therefore is compatible with any enzyme that produces GDP, including GTPases such as CDC42. The Transcreener GDP Assay is a simple one step homogenous detection assay, and is extremely flexible with regard to GTP concentration (1 to 1,000 µM GTP). The assay provides excellent signal at low substrate conversion, with a Z' > 0.7 and >85 polarization shift (mP) at 10% GTP conversion using 10 µM GTP. The Transcreener GDP Assay was developed to follow the progress of any enzyme that produces GDP. The Transcreener GDP Detection Mixture comprises a GDP Alexa633 Tracer bound to a GDP Antibody. The tracer is displaced by GDP, the invariant product generated during the enzyme reaction. The displaced tracer freely rotates leading to a decrease in fluorescence polarization. Therefore, GDP production is proportional to a decrease in polarization. The assay uses a far red tracer to minimize interference from fluorescent compounds and light scattering.