Surface Plasmon Resonance based CreMap™ Epitope Mapping Service

Background Method Key Features Published Data FAQ Resources

Creative Biolabs helps to figure out epitopes by providing mapping services with Surface Plasmon Resonance (SPR) technology that is quite useful in the evaluation of antigen-antibody interaction, affinity measurement, competition assays, ligand fishing, ADME (adsorption, distribution, metabolism, and excretion) characterization.

Background

SPR is the resonant oscillation of conduction electrons at the interface between negative and positive permittivity material stimulated by incident light. SPR allows for the analysis of the association and dissociation rate constants and modeling of biomolecular interaction kinetics. For epitope mapping analysis, the antigen is typically immobilized on a sensor chip surface, and the antibody flows through a microfluidic system in contact with the chip surface. SPR measures in real time the changes in mass bound to the sensor chip. It detects the changes in refractive index of the surface layer of a solution in contact with the sensor chip that is caused by a variation of the mass on the sensor chip surface. SPR immunoassay resembles the concept of the ELISA technique, but it is label-free, eliminating the requirement for reporter molecules or tags which could be time-consuming and even alter the molecular interaction.

CreMap™ Epitope Mapping by Surface Plasmon Resonance Fig.1 The schematic of the surface plasmon resonance measurement.

Method

Surface plasmon resonance (SPR) is a label-free optical sensing technique to characterize binding between a soluble ligand and a surface-immobilized receptor.

The antigen is immobilized on the surface of the sensor chip.
The antibody flows through the microfluidic system.
The antibody binds the candidate antigen at the interface causing an increase in refractive index, which results in a shift in resonance angle and a change in the SPR signal.
SPR signal changes as a function of time are collected by the detector and allow the calculation of association (k_a) and dissociation (k_d) rate constants.
k_a and k_d constants are used to determine affinity and epitopes.

Key Features

Label-free: one of the main features of SPR used for epitope mapping is that SPR detects the interaction between the antigen and antibody with no labels.
Low purity requirement: the purified sample is ideal for identification, but purified samples are not always available. SPR can be applied to test crude samples, reducing the time and cost spent on purifying samples. SPR stands out as one of the best options when the antigen purification is not possible.
Small amounts of reagents required: only a small amount of samples are required for SPR to run the epitope mapping analysis, reducing the cost of expensive materials and making SPR more affordable.

SPR is a powerful method for characterizing the epitopes on the antigen.Scientists from Creative Biolabs have been working on developing and optimizing our SPR platform to better serve growing demands of customers around the world. If you are trying to figure out epitopes on the antigen, or if you are interested in our platform, please feel free to contact us by sending E-mail. A formal feedback will be sent back as soon as possible.

Other optional CreMap™ B cell epitope mapping services:

Published Data

Identification of Human Antibodies Against ATβ*H by SPR and ELISA

Fig. 2 TPP2009 specifically binds antithrombin III (AT)β in a heparin‐dependent manner. (Y. Jin, 2016)

The study utilizes Surface Plasmon Resonance (SPR) for epitope mapping to specifically investigate the interaction of a novel conformation-specific antibody, TPP2009, with Antithrombin IIIb (ATb) when bound to heparin. This research demonstrates that TPP2009 can selectively bind to ATbH and effectively block ATb-mediated anticoagulation, suggesting a targeted therapeutic approach for conditions involving excessive clotting. The results show that TPP2009 specifically targets a unique conformational epitope on ATbH, significantly reducing its anticoagulant effect and thereby enhancing coagulation in plasma. This selective inhibition is pivotal in developing interventions that manipulate hemostasis precisely at sites of vascular injury, potentially providing a novel strategy for managing thrombotic diseases.

References

Wittenberg, N.J., et al., Applications of SPR for the characterization of molecules important in the pathogenesis and treatment of neurodegenerative diseases. Expert Rev Neurother, 2014. 14(4): p. 449-63.
Cooper, M.A., Optical biosensors in drug discovery. Nat Rev Drug Discov, 2002. 1(7): p. 515-28.
Stahelin, R.V., Surface plasmon resonance: a useful technique for cell biologists to characterize biomolecular interactions. Mol Biol Cell, 2013. 24(7): p. 883-6.
Myszka, D.G., Kinetic analysis of macromolecular interactions using surface plasmon resonance biosensors. Curr Opin Biotechnol, 1997. 8(1): p. 50-7.
Jin, Y., et al. "Identification and function probing of an antithrombin IIIβ conformation‐specific antibody." Journal of Thrombosis and Haemostasis 14.2 (2016): 356-365.

FAQ

What is epitope mapping by Surface Plasmon Resonance (SPR)?
Epitope mapping by SPR is a method that identifies the specific parts of an antigen that antibodies recognize and bind to. It involves the real-time monitoring of binding events between an antigen and antibody, without the need for labeling, providing detailed insights into the molecular interactions at the epitope level.
How does SPR work for epitope mapping?
In SPR epitope mapping, an antigen is typically immobilized on a sensor chip and various antibodies are flowed over the surface. SPR measures changes in the refractive index near the sensor surface, which occur when antibodies bind to the antigen. This data helps identify which parts of the antigen are involved in binding.
What are the advantages of using SPR for epitope mapping?
SPR allows real-time monitoring of binding interactions, requires minimal sample preparation, and provides quantitative data on binding kinetics and affinity. It can also be used to study interactions under near-physiological conditions, making it highly relevant for therapeutic antibody development.
Can SPR differentiate between similar epitopes?
SPR is sensitive enough to differentiate between closely related epitopes. By analyzing the binding kinetics and affinity of antibodies to specific antigen regions, SPR can distinguish subtle differences in antibody-antigen interactions, even among closely spaced or similar epitopes.
What types of samples can be analyzed using SPR for epitope mapping?
SPR can analyze a wide range of biological samples including proteins, peptides, small molecules, and even cells. For epitope mapping, the antigens and antibodies used are typically purified proteins or peptides, which are stable under the conditions used in the SPR experiments.
Is SPR suitable for high-throughput epitope mapping?
Modern SPR instruments are equipped with multiple flow channels and automated sample handling systems, enabling high-throughput analysis. This allows for simultaneous testing of multiple antibodies against a single antigen or screening of several antigens in a single experiment.
Can SPR detect conformational changes in antigens during binding?
SPR can indirectly detect conformational changes in antigens during antibody binding through changes in the sensorgram, which may indicate complex formation or dissociation kinetics that deviate from expected patterns. Additional experiments, such as mass spectrometry, might be necessary to confirm these findings.