Binding Kinetics Analysis

Binding kinetics describes the dynamic interaction between two biomolecules (e.g., protein-ligand, antibody-antigen) by quantifying the association rate (Kon), dissociation rate (Koff), and equilibrium dissociation constant (K_D). These parameters define how rapidly a complex forms, how long it remains stable, and the overall binding strength. Unlike equilibrium affinity, kinetics reveal the temporal behavior of interactions, which is critical for understanding drug efficacy, target residence time, and therapeutic durability. For example, drugs with slow Koff (long target residence) often exhibit prolonged pharmacodynamic effects, even at low concentrations.

Illustration of a typical sensorgram of surface plasmon resonance (SPR) measurement. (STEMart Original) Fig.1 A typical sensorgram of surface plasmon resonance (SPR) measurement. (STEMart Original)

STEMart’s Binding Kinetics Services

Illustration of stemart’s binding kinetics services. (STEMart Original)

STEMart provides end-to-end solutions for kinetic characterization:

High-Throughput Screening: Rapid profiling of Kon and Koff using SPR, BLI, or GCI platforms.
Regeneration-Free Assays: Implement waveRAPID to eliminate sensor regeneration steps, saving time and sample.
Live-Cell Kinetics: Study real-time target engagement with NanoBRET or TR-FRET in physiologically relevant environments.
Data Analysis: Advanced software (e.g., Direct Kinetics) for global fitting of multi-concentration datasets.
Regulatory Compliance: ICH Q2(R1)-aligned reports for IND/NDA submissions.

Our Techniques

Surface Plasmon Resonance (SPR)

SPR measures real-time binding by detecting refractive index changes near a sensor surface. Ligands are immobilized on a chip, and analytes flow over them. Sensorgrams track association Kon and dissociation Koff phases to calculate KD.

Gold standard for label-free, high-resolution kinetics.
Ideal for membrane proteins, antibodies, and small-molecule screening.

Biolayer Interferometry (BLI)

BLI uses optical biosensors to measure binding-induced shifts in interference patterns. Ligands are immobilized on sensor tips, and analytes in solution are monitored in real time.

Rapid, low-volume screening for crude samples (e.g., cell lysates).
Suitable for kinetic profiling of antibody-antigen interactions.

Grating-Coupled Interferometry (GCI)

GCI analyzes phase shifts between reference and sample light beams in a waveguide. Binding alters the refractive index, enabling precise kinetic measurements without regeneration steps.

waveRAPID technology accelerates analysis by using repeated analyte pulses of increasing duration, reducing assay time by 50% while maintaining accuracy.

Fluorescence Polarization (FP)

FP tracks rotational speed changes of a fluorescent ligand upon binding to a larger protein. Polarization increases as complexes form, allowing calculation of Kon and Koff.

Homogeneous, high-throughput screening for small-molecule inhibitors or peptide ligands.

Microscale Thermophoresis (MST)

MST detects binding-induced changes in protein mobility under a temperature gradient. Fluorescently labeled molecules exhibit altered thermophoresis upon complex formation.

Works in native conditions (e.g., serum) with minimal sample use.
Ideal for low-solubility targets.

Isothermal Titration Calorimetry (ITC)

ITC quantifies heat exchange during binding to derive thermodynamic parameters (ΔH, ΔS) and stoichiometry. While primarily an affinity tool, it supports kinetic insights via stepwise titration.

Label-free analysis of protein-protein or small-molecule interactions.

Why Choose STEMart

Cutting-Edge Platforms: WAVEsystem, GCI, and MST for high-resolution, label-free kinetics.
Expertise in Complex Targets: Membrane proteins, aggregates, and low-abundance analytes.
Customized Workflows: Tailored assays for soluble, cell-bound, or viscous formulations.

Binding kinetics analysis bridges molecular interactions with therapeutic outcomes, enabling the design of drugs with optimized efficacy and safety. STEMart uses advanced technologies to deliver actionable insights, accelerating drug development from discovery to commercialization.

For more information on our Binding Kinetics Analysis service or to discuss your specific requirements, please contact us today.