GPCR ligand binding
Roughly a third of approved drugs act on a GPCR.
Build a GPCR binding assay that measures ligand association and dissociation against the receptor.
receptor-ligand kinetics
lipid bilayer
GPCR ligand binding and membrane protein kinetics, in a lipid environment
Take a receptor out of the membrane and it stops behaving like itself. Expression yields are low, the lipid environment is fragile, and there is rarely enough material for a second attempt. Lipid bilayer sensors on the inQuiQ make GPCR ligand binding measurable on a receptor that stays in its lipid environment.
Applications in membrane protein drug discovery
Receptor ligand kinetics reveal selectivity and residence time, while membrane targets are harder to characterize. The inQuiQ supports GPCR ligand binding in lipid environments, with label-free analysis for GPCR binding and receptor binding kinetics.
Ion channel binding assays and transporters
Characterize binding to channels and solute carriers.
modulator ranking
Receptor tyrosine kinases
Work with EGFR, HER2, and related receptors.
Measure antibody or ligand binding to the ectodomain and compare binding affinity and kinetics.
EGFR, HER2
Cytokine and Fc receptors
Measure engagement at the cell-surface receptor.
Compare candidate variants against the same receptor preparation.
variant ranking
Nanodisc and SMALP preparations
Confirm that nanodisc reconstitution leaves the receptor still binding.
Check a new preparation before a larger campaign.
nanodisc capture
Don't see your system?
Discuss your assay with one of our application specialists.
Talk to a specialist
Benefits of the inQuiQ in membrane protein analysis
01 / 04
One injection, four channels, sixteen sensors
Four independently addressable flow channels, each carrying four sensors, with the sample flowing through the channels in series.
30 µL minimumsequential flow paths
Run a lipid binding assay in a lipid environment
Membrane proteins need a sensor surface built for them, either compatible with a lipid mono- or bilayer, or able to capture a nanodisc with the receptor still functional.
lipid-compatible surfacenanodisc capture
bilayer, or captured nanodisc
Read a small response from a low-yield preparation
Expression yields for membrane proteins are usually low, so the binding response is small. Baseline noise sits at 0.1 RU RMS, and the sensor is regenerated between injections rather than replaced.
0.1 RU RMS30 µL
small response, low noise
Watch receptor ligand kinetics and binding affinity
The sensorgram gives the full kinetics picture. Binding ffinity runs from 10 pM to 10 mM, with steady-state fitting where dissociation is too fast for kinetics.
ka, kd, KD10 pM to 10 mM
association, then dissociation
How a membrane protein binding run works
Every measurement on a lipid bilayer sensor follows the same steps. The receptor is immobilized in a lipid bilayer on the sensor, the ligand flows past, and the response is recorded through the whole injection.
Immobilization
The receptor is delivered into a bilayer formed across the sensor.
For GPCR and membrane protein binding kinetics analysis, proteoliposomes fuse on the chip to leave a continuous supported bilayer over the waveguide, with the receptor sitting in it in native orientation.
- vesicle fusion
- supported bilayer
Deactivation
Bare patches left in the layer are blocked before the first ligand sample arrives.
Defects expose the surface underneath, and detergent, free lipid, and buffer components adsorb there readily. That appears in the sensorgram as non-specific binding rather than as receptor engagement.
- bilayer defects
- blocking
- non-specific binding
Association
The ligand flows across the surface and the response climbs.
The association phase gives the on-rate, ka, for receptor-ligand binding. A reference channel carrying a protein-free bilayer of the same lipid composition separates ligand binding from binding to the membrane itself.
- protein-free bilayer reference
- referencing
- ka
Dissociation
Buffer replaces the ligand and the response falls as the complex comes apart.
The dissociation phase gives kd, and 1/kd gives residence time, the number that separates two GPCR ligands sharing a KD. Single-cycle kinetics runs the series uninterrupted when the preparation is scarce.
- residence time
- kd
- KD
- SCK
Regeneration
A mild regeneration buffer returns the sensor to baseline for the next ligand.
The bilayer and the receptor in it stay intact, so every ligand meets the same surface. Conditions are kept gentle, since the lipid environment is what makes the measurement worth having.
- mild regeneration
- bilayer stability
- automated cycling
Response (RU)
Time
What the inQuiQ does for membrane protein work
Six capabilities, one modular benchtop instrument, in a label-free workflow.
Many constructs, one limited prep
Four channels with in-flow immobilization, or sixteen sensors with a spotter, compare constructs and controls from one injected sample.
16 sensors (spotter required)
30 µL
Detect low-abundance targets
Baseline noise stays low enough that a small binding response is still readable.
0.1 RU RMS
Full kinetics from limited material
One affinity range covers weak modulators through tight ligands, with kon and koff from the same injection series.
10 pM to 10 mM
A surface that holds a membrane
Sensor surfaces compatible with lipid mono- and bilayers, or able to capture nanodiscs, keep the receptor functional.
lipid-compatible surface
nanodisc capture
Stable across a long series
The temperature-controlled flow cell holds conditions steady while a fragile preparation is measured over many injections.
temp. control from 16 to 40 °C
Modular system for an increased throughput
Simply add an autosampler, and run a long construct or condition series unattended.
2×96 wells
2×384 wells
Explore the inQuiQ768
Application notes, publications, and data
From small molecule kinetics to antibody affinity, explore real binding data generated on the inQuiQ. Each application note pairs a sensorgram with the affinity and kinetic values behind it.
Start A conversation
Talk to an application scientist
Bring your receptor. We will tell you honestly whether label-free is the right method for it, and how the assay would be built.
Ready to see the inQuiQ in action?
Talk to an application scientist
Thirty minutes to discuss your assay design, before anyone mentions an instrument.
Download the inQuiQ brochure
Sensitivity, channel layout, footprint, and consumable formats in a couple of pages.
Delta Life Science
request@deltalifescience.nl
Send us an email, and we will get back to you as soon as possible.
request@deltalifescience.nl
Send us an email, and we will get back to you as soon as possible.
Questions researchers ask
Capture the receptor on a lipid-compatible sensor surface, or capture the nanodisc carrying it, then inject the ligand across a concentration series. The association phase gives kon, the dissociation phase gives koff, and the two together give KD. Affinity on the inQuiQ runs from 10 pM to 10 mM.
Keep it in a lipid environment. Detergent micelles, nanodiscs, and SMALPs all preserve the folded receptor, and the sensor surface has to suit them. A standard hydrogel chip does not, so membrane work uses a surface built for lipid mono- and bilayers or for nanodisc capture.
Yes, on a label-free biosensor with a sensor surface designed for it. The particle is captured through a tag on the receptor or on the scaffold, and the ligand is then injected over it. A reference channel carrying empty particles separates binding to the receptor from binding to the lipid or the scaffold.
The inQuiQ runs from 30 µL of sample per injection. Sensors are regenerable, so one prepared surface carries a series of ligands, concentrations, and controls rather than one measurement per surface. That matters when expression yield is the limit on the experiment.
Affinity (KD) says how tightly ligand and receptor bind at equilibrium. Kinetics says how they get there: kon for how fast the complex forms, koff for how fast it falls apart. A receptor ligand binding assay reported as KD alone hides that, because two ligands with the same KD can have very different residence times.