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View This Webinar on The Transcreener Method For Screening and Profiling GTPases

KRAS Assay - A Transcreener GDP Assay Application

Transcreener GDP Assay directly measures GDP produced by KRAS (Kirsten Rat Sarcoma Virus Oncogene Homolog). These GDP measurements allow researchers to effectively determine the activity of the KRAS enzyme. The assay provides a powerful tool to screen compound libraries for KRAS modulators to help find new therapies for disease.

The kit comes complete with the detection reagents required to measure activity. KRAS enzyme is not included in the inhibitor screening assay kit. Please contact us for questions related to acquiring the enzyme.

This assay is designed to be used with purified enzyme preparations. Transcreener assays are not validated with cell lysates, blood, serum, or other biological samples.

KRAS Enzyme Reaction Cycle

KRAS Assay On Off Schematic

How Does This KRAS Assay Work?

The Transcreener KRAS Assay determines KRAS enzyme activity by directly measuring the GDP formed by the enzyme using the Transcreener GDP Assay. By detecting GDP output, the assay provides a universal method to assess the activity of any GDP-producing enzyme in real time. 

Transcreener KRAS Assay technology uses a simple but highly effective method that consists of an antibody selective to GDP and a far-red fluorescent tracer. GDP produced in the reaction competes with the tracer changing the fluorescent properties and providing fluorescent readout.

The KRAS assay is available with FP, FI, and TR-FRET. It is an easy-to-use mix-and-read format. Perform your enzyme reaction, add the detection reagent, and measure. The simplicity of the system yields robust results that also make it extremely amiable to HTS.

Direct Detection of GDP to Measure KRAS Enzymatic Activity

Fluorescent Polarization (FP)

Assay Schematic of Transcreener KRAS Assay

The workhorse. Used in many large screens. Best deck and signal stability.

Fluorescent Intensity (FI)

Transcreener KRAS FI Readout

Positive FI signal. Compatible with simple fluorescence plate readers. Faster read time than FP or TR-FRET.

Time-Resolved Förster Resonance Energy Transfer (TR-FRET)

Transcreener KRAS Assay TR-FRET Readout

For customers who prefer TR-FRET detection. Uses the same filter set as HTRF®.

Applications

  • Measure Enzymatic Activity of KRAS
  • Screen Compound Libraries for KRAS Modulators
  • Quantify Inhibitor Potency
  • Inhibitor Selectivity Profiling
  • Measure Drug-Target Residence Time

Features

  • Direct detection of unlabeled GDP
  • Easy to use, homogenous, one-step format
  • Robust Assay Z’ > 0.7 under initial velocity conditions
  • Far-red fluorescent readouts minimize compound interference
  • A safe, non-radioactive method
  • Available in FP, FI, or TR-FRET readouts

Easy-to-Use, Mix-and-Read, HTS-Ready Assay

Run your enzyme reaction, add Transcreener reagents, and read your plates. The KRAS assay is compatible with 96, 384, and 1536-well formats.

Transcreener Mix and Read Assay

Detection of GDP Released By KRAS (EDTA Concentration Dependence)

EDTA enhances the GDP exchange and GTP hydrolysis of some GTPases. The assay conditions below are chosen to generate the best assay window and ability to study the enzyme. The assay demonstrates linearity when raw data is converted to GDP using a standard curve. Here we use 2 µM GTP. Linearity is shown here under initial velocity conditions when raw data is converted to GDP formed. The enzyme buffer includes 20 mM Tris pH 7.5, 50 mM NaCl, 5 mM MgCl2, 0.1 mg/mL BSA, and 1 mM DTT. The Detection mix included 10 μg/mL GDP antibody and 4 nM GDP Alexa 633 tracer. The KRAS enzyme reaction took place for 60, 120, and 180 minutes. The Detection Mix was added with the substrate to start the reaction and incubated at 30°C. Readings were taken with a CLARIOstar plate reader.

KRAS Enzyme Titration

KRAS Assay Enzyme Titration Curve Concentration Dependence

Linear Response

KRAS Linear Response Curve Concentration Dependence

Optimal Assay Conditions: 130 nM KRAS for 2 hours with 20 mM EDTA

Detection of GDP Released By KRAS (Time Dependence)

The assay demonstrates linearity when raw data is converted to GDP using a standard curve. Here we use 2 µM GTP. The enzyme buffer includes 20 mM Tris pH 7.5, 50 mM NaCl, 5 mM MgCl2, 0.1 mg/mL BSA, and 1 mM DTT. The Detection mix included 10 μg/mL GDP antibody and 4 nM GDP Alexa 633 tracer. 20 mM EDTA was used based on the concentration dependent curve. The KRAS enzyme reaction took place for 60, 120, and 180 minutes. The Detection Mix was added with the substrate to start the reaction and incubated at 30°C. Readings were taken with a CLARIOstar plate reader.

KRAS Enzyme Titration

KRAS Enzyme Titration Curve Time Dependence

Linear Response

KRAS Linear Response Curve Time Dependence

Optimal Assay Conditions: 130 nM KRAS for 2 hours with 20 mM EDTA

KRAS Assay Services

Interested in moving your program forward, but don't want to bring an assay in-house? Our scientists can help! BellBrook scientists will use their extensive biochemistry and enzymology expertise to work with you and accelerate your KRAS program (right here in Madison, Wisconsin). We can provide modulator potency profiling for KRAS, along with a variety of other GTPase enzymes, related GAPs, GEFs, and other proteins. Get accurate IC50 results fast to understand how your lead molecule interacts with other GTPases. 

Assay Development Services

Contact Us to Learn More

Contact us today to see if BellBrook's KRAS profiling services will advance your research. We will respond quickly to get the conversation moving and learn how we can help. We keep things discrete, confidential, and professional.

Far-Red FP, FI & TR-FRET Readouts Validated on Major Multimode Readers

SupplierInstrumentFP AssaysFI AssaysTR-FRET Assays
TriStar2S LB 942In ReviewClick Me ArrowValidatedClick Me ArrowValidated
Tristar 5In ReviewClick Me ArrowValidatedIn Review
Mithras2 LB 943In ReviewClick Me ArrowValidatedClick Me ArrowValidated
CytationTM 5ValidatedValidatedValidated
CytationTM 3ValidatedValidatedValidated
CytationTM 1ValidatedValidatedValidated
SynergyTM H1ValidatedValidatedValidated
SynergyTM 2/H4/4Click Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
SynergyTM HTXNot CapableValidatedNot Capable
SynergyTM Neo 2ValidatedValidatedValidated
POLARstar® OmegaClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
FLUOstar® OmegaNot CapableClick Me ArrowValidatedClick Me ArrowValidated
PHERAstar® FSXClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
PHERAstar® Plus/FSClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
CLARIOstar® /PlusClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
VANTAstarTMClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
SenseIn ReviewClick Me ArrowValidatedIn Review
Analyst® GT/HTClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
Gemini® XPS/EMNot CapableClick Me ArrowValidatedNot Capable
SpectraMax® M2/M2eNot CapableClick Me ArrowValidatedNot Capable
SpectraMax® M5/M5e/FlexStation® 3Not CapableClick Me ArrowValidatedClick Me ArrowValidated
SpectraMax® ParadigmClick Me ArrowValidatedClick Me ArrowContact UsClick Me ArrowContact Us
SpectraMax® iD3/iD5Click Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
SpectraMax® i3xClick Me ArrowValidatedIn ReviewClick Me ArrowValidated
EnVision®/EnVision® XciteClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
Infinite® M1000/M1000Pro/Safire2TMClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
Infinite® M200Not CapableClick Me ArrowValidatedNot Capable
Infinite® F500Click Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated
Infinite® F200/UltraevolutionClick Me ArrowContact UsClick Me ArrowValidatedClick Me ArrowContact Us
SparkTM 10MClick Me ArrowValidatedClick Me ArrowValidatedClick Me ArrowValidated

What's Included

What You Will Need

The Role of KRAS As a Therapeutic Target

KRAS, the oncogene, has the highest mutation rate among all cancers. Related to the high mutation rate, KRAS is linked to many fatal cancers, including pancreatic ductal adenocarcinoma, non-small cell lung cancer, and colorectal cancer. Advancements in KRAS as a drug target show potential for treating many life-threatening tumors (Huang et al, 2021).

KRAS was once deemed "undruggable" due to its intrinsic protein factors. A recent discovery of a new allosteric binding site on KRAS mutation KRAS (G12C) reignited interest in KRAS and KRAS inhibitors for therapeutic cancer treatments. The drug AMG510 (Sotorasib), which specifically targets this mutation, was the first KRAS drug approved for clinical use (Huang et al, 2021). 

The Transcreener GDP KRAS Assay is an excellent tool for researchers examining KRAS for therapeutic treatments.

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