Targeting LRRK2 for Parkinson’s Disease with the Transcreener® GDP GTPase Assay

The Only Mix-and-Read Fluorescent GTPase Assay

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

Universal GDP Detection for GTPases


Assay Tunable to Your Target

GTP to GDP Standard Curve

Standard curves mimicking the enzymatic conversion of GTP to GDP using the Transcreener GDP FP Assay. The dynamic range of the assay can be easily tuned for different initial GTP concentrations.

Single Step - Mix-and-Read

GDP GTPase Assay Schematic

Turnkey Protocol: Run enzyme reaction, add detection reagents, and read plates

Use with a Variety of GTPases

Cdc42 RhoA GTPase Enzyme Titration

Cdc42 and RhoA GTPase titration using the Transcreener GDP Assay with an FP readout.

Three Readouts Available

  • Fluorescence polarization (FP)
  • Fluorescence intensity (FI)
  • Time-resolved Forster-resonance-energy-transfer (TR-FRET)

Assay Features

  • Easy-to-Use, Ultra-Sensitive GTPase Activity Assay
  • HTS Compatible with 96, 384, and 1536-well plates
  • Direct detection of GDP to monitor GTPase, GAP, and GEF Activity
  • Stable assay reagents – minimum 8-hour reagent and signal stability