Targeting the cGAS-STING Pathway Using a Homogenous, HTS Compatible Transcreener cGAS Assay

Discover cGAS Inhibitors with the Transcreener cGAMP cGAS Assay

The Transcreener cGAMP cGAS Assay directly measures cyclic GMP-AMP (cGAMP) produced by cyclic GMP-AMP synthase (cGAS). By measuring the production of cGAMP researchers can effectively determine the activity of the cGAS enzyme. The assay provides a powerful tool to screen entire compound libraries for cGAS modulators to help find new therapeutics targeting the cGAS-STING pathway.

cGAS is an Important Messenger in the STING Pathway

The presence of DNA in the cytosol of eukaryotic cells is an indicator of infection or cellular damage, and it elicits a robust immune response, driven by type I interferon (IFN) induction. cGAS is an exquisitely sensitive sensor for double-stranded DNA in the cytoplasm. Binding of DNA activates the enzyme to produce a unique cyclic dinucleotide second messenger, cGAMP, which acts as an agonist for the STING (stimulator of interferon genes) receptor, leading to induction of a type I interferon response.

Direct Detection of cGAMP to Measure cGAS Enzymatic Activity

Transcreener cGAMP FP Assay - LEARN MORE

Transcreener cGAMP cGAS FP Assay Technical Manual (PDF)

cGAMP TR-FRET Assay - COMING SOON

Applications

Measure Enzymatic Activity of cGAS
Screen Compound Libraries for cGAS inhibitors
Quantify Inhibitor Potency
Determine Inhibitor-cGAS Residence Time

Features

Direct detection of unlabeled cGAMP
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 or TR-FRET readouts

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

The Transcreener cGAS Assay is in a simple, HTS-ready, mix-and-read format. Run your enzyme reaction, add Transcreener reagents, and read your plates. The assay is compatible with 96, 384, and 1536-well formats.

Detection of cGAMP Under cGAS Initial Velocity

The assay demonstrates linearity when raw data is converted to cGAMP using a standard curve. cGAS is activated by double-stranded DNA and requires ATP and GTP substrates for the production of cGAMP.

Full-Length Human cGAS Titration

Linear Response

cGAS Enzyme Titration Initial Velocity Conditions

Screen for Inhibitors & Perform SAR

The Transcreener cGAS Assay is designed for screening compound libraries in a high throughput format. Follow up SAR can also be performed using the assay to determine inhibitor potency with ease.

1600 Compound Pilot Screen

Acquire Accurate Dose Response Measurements

Illustrates DNA & Substrate Dependance of the cGAS Enzyme

The assay accurately demonstrates the characteristics of the cGAS enzyme. Double-stranded DNA activates the enzyme which generates cGAMP in the presence of both GTP and ATP. A 45 base pair ISD (interferon stimulatory DNA) and a 60 base pair HSV (herpes simplex virus) DNA both activate the enzyme. The assay has a high affinity to cGAMP and can detect even in the presence of other nucleotides.

cGAS Enzyme Activation by dsDNA

Dependence on ATP and GTP

Outstanding Signal Stability

The assay exhibits 24 hours+ signal stability. Plate stability like this is vital for sizeable high throughput screens that take significant time to complete due to massive sample quantity.

Standard curves include ATP, GTP, dsDNA, and titration of cGAMP. The same plate was read at each time point.

Measure Inhibitor Residence Time With a Simple Biochemical Assay

The Transcreener cGAS Assay can be used to measure drug-target residence time using the jump-dilution method. Because the assay can be used in kinetic mode, enzymatic activity can be measured as the enzyme regains activity once the inhibitor dissociates.

Get the Guide to Learn More About Residence Time

The basics of residence time and its importance to drug discovery
A comparison of methods used for residence time determination
Using the jump-dilution method with Transcreener biochemical assays
Data analysis used to accurately determine residence time
Examples of measuring residence time for kinases, phosphodiesterases, and glycosyltransferases

A Guide to Measuring Drug-Target Residence Times with Biochemical Assays

Download the Guide

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

What's Included

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Component	Notes
cGAMP Antibody	Antibody specific to the dinucleotide cGAMP.
Tracer	When displaced, changes in fluorescence can be read in an FP or TR-FRET depending on the assay format.
Stop & Detect Buffer B, 10X	A buffer that can be used to stop enzyme reactions for an endpoint readout.
ATP	ATP can be used for the enzyme reaction and standard curve.
GTP	GTP can be used for the enzyme reaction and standard curve.
cGAMP	cGAMP can be used to create a standard curve.
Interferon Stimulatory DNA	ISD is a 45-bp oligomer used to activate the cGAS enzyme.

What You Will Need

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Component	Notes
cGAS Enzyme	You can purchase active *cGAS enzyme* directly through BellBrook Labs.
Enzyme Buffer	We routinely use enzyme buffer containing 20 mM TRIS (pH 7.5), 5 mM MgCl₂, 0.01% Brij-35, and 1% DMSO (test compound solvent). Use the buffer that is a best fit for your enzyme conditions
Assay Plates	FP - An entirely black plate with a non-binding surface is required. We suggest Corning 384-well plates, Cat. #4514

Transcreener cGAMP cGAS Assay Kits

* For custom or bulk orders (over 100,000 wells) please contact us (info@bellbrooklabs.com) for a quote.

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Cat. No.	Product Description	Price	Add to Cart
3024-1k	Transcreener cGAMP cGAS FP Assay (1,000 Assay, 384 Well)	$798.00	Add to Cart
3024-10k	Transcreener cGAMP cGAS FP Assay (10,000 Assay, 384 Well)	$4,615.00	Add to Cart
3024-100k	Transcreener cGAMP cGAS FP Assay (10 X 10,000 Assay, 384 Well)	$23,075.00	Add to Cart

cGAS Enzyme Ordering Information

* For custom or bulk orders (over 100 μg) please contact us (info@bellbrooklabs.com) for a quote.

Edit
Cat. No.	Product Description	Price	Add to Cart
2227	Recombinant cGAS Enzyme, Active, Human, Full-Length, 10 µg	$399.00	Add to Cart
2228	Recombinant cGAS Enzyme, Active, Human, Full-Le ngth, 100 µg	$2594.00	Add to Cart

Learn More About Active Human cGAS Enzyme

Go to cGAS Enzyme Page

cGAS Screening Bundles

* Includes enough enzyme for respective wells when used at 1.75 μg/mL (30 nM)

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Cat. No.	Product Description	Price	Add to Cart
3024-1K-B	Includes Transcreener cGAS Assay 1K Kit and 20 µg cGAS Enzyme	$1,275.00	Add to Cart
3024-10K-B	Includes Transcreener cGAS Assay 10K Kit and 200 µg cGAS Enzyme	$7,839.00	Add to Cart

In addition to our cGAMP cGAS Assay, Bellbrook Labs also offers the following products to aid in the drug discovery process:

Transcreener® cGAMP cGAS Assay