Creative Biolabs has developed an advanced phage display platform for phage display library construction and phage display library screening. Our scientists have developed using a variety of strategies to identify target-binding peptides for soft matter. Equipped with world-leading technology platforms, Creative Biolabs can provide high-quality service of determination of the affinity of identified peptides to soft matters, including synthetic and natural polymers, as well as small organic molecules and inorganic molecules.
The Introduction of Four Techniques for Characterization
There are four methods commonly used to characterize the affinity of peptide ligands towards soft matter surface, such as surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), atomic force microscopy (AFM) and quartz crystal microbalance (QCM).
SPR is an advanced optical technique that is predominantly applied for the real-time determination of the affinities of ligands in solution to surface-immobilized substrates. From the determination of the rate constant of association (kass) and the rate constant of dissociation (kdiss) values, the binding constant can be calculated (Ka = kass/kdiss). It is a very powerful tool for the investigation of degradation, adsorption or hydration processes of synthetic or natural polymeric films, as well as for the characterization of ligands that selectively bind to these substrates. One of the advantages of SPR is that it does not require chemical modification of the ligand or the substrate and does not rely on the signal of any reporting molecule.
ITC is a powerful technique that allows the determination of the thermodynamic interaction parameters between two or possibly more components in solution. An isothermal titration calorimeter consists of two cells, the reference cell, which only contains a buffer solution, and the sample cell, which is loaded with the substrate of interest at a defined concentration in the same buffer solution. The method depends on the measurement of the temperature difference of gradual titration of the substrate with the corresponding ligand until saturation is reached.
Due to its ability to accurately measure forces in the pico-newton range, AFM can be widely used to determine the strength of non-covalent ligand-substrate interactions. AFM tips are used to determine the unbinding force between the ligand and the substrate and substrates that are functionalized with the respective molecules. Briefly, an AFM measurement cycle reveals a hysteresis between the force-distance curves and retraction of the AFM tip, which is required to separate an interacting pair immobilized to the tip and the substrate at a given loading rate. AFM is a powerful complementary technique to study the interaction between phages or peptide ligands and surfaces.
QCM allows the determination the mass of material that is adsorbed or deposited on a surface from the change in resonance frequency of an oscillating quartz crystal. The QCM technique can also be used in liquid solutions, making it an attractive tool to study interfacial phenomena. The QCM technique has been widely utilized to assess the interaction between antibody presenting phages and the complementary antigens. This technique represents a powerful method to obtain (semi-)quantitative insight into the binding affinities of soft matter binding peptides.
Key Advantages of Characterization of the Affinity
In the field of applying phage display technology, Creative Biolabs has accumulated extensive experiences. Equipped with world-class platforms and professional scientific staff, we can provide the best service of determination of the affinity of identified peptides to soft matters at the most competitive cost. For more detailed information, please feel free to contact us or directly send us an inquiry.