The Transcreener GDP GTPase assay is a homogenous, fluorescent immunoassay that monitors the activity of GTPases along with GEF and GAP partners. The assay directly measures the amount of GDP produced in an in vitro GTPase reaction.

The assays are available with fluorescence polarization (FP), fluorescence intensity (FI), and far-red, time-resolved Forster-resonance-energy-transfer (TR-FRET) readouts that provide a safe, HTS-compatible alternative to cumbersome radioassay methods and are more sensitive and less subject to interference than colorimetric phosphate detection methods.

Based on BellBrook Lab's proprietary nucleotide immunodetection technology, the Transcreener GDP GTPase Assays are compatible with any enzyme class that produces GDP, including monomeric small G proteins, such as CDC42, and Gα subunits of heterotrimeric G proteins, such as Gαi1.

GDP displaces tracer from a highly selective monoclonal antibody resulting in a decrease in fluorescence polarization or an increase in fluorescence intensity.

• Measure guanine nucleotide exchange factor (GEF) activity
• Measure GTPase-activating proteins (GAP) activity
• Homogenous, simple, mix-and-read assay
• Tunable dynamic range to match the target of interest
• Detect any GDP producing enzyme: GTPases, fucosyltransferases, mannosyltransferases