Optical Tools for Studying Bimolecular Interactions

Direct interactions between biological molecules are required for the implementation and regulation of the molecular mechanisms underpinning biological activities. Specific binding between at least one molecule and another characterizes these interactions; the molecules must be able to approach near enough to each other to make contact.

Importantly, both may be used for label-free molecules and real-time studies of binding kinetics. The approaches have many similarities, making it difficult to select between them. On the other hand, they can occasionally be utilized to complement each other.

Studying biomolecular interactions:

Once an understanding of biomolecular interaction behaviour has been developed, additional opportunities for using this new information emerge. Biomolecular interactions are important in applied sciences, such as drug discovery and development, and this information may be utilized to find targets for novel compounds and detect possible new pharmaceutical prospects.

Specific binding between at least one molecule and another characterizes these interactions, and for binding to occur, the molecules must be able to approach near enough to each other to make contact. One of the interaction partners is always a macromolecule or a big assembly, such as a lipid bilayer.

The interaction can take place with the partners in solution or with at least one extremely big structure attached to a biological surface, such as a chromosome. If the partners are part of a membrane or other big structure, there must be a mechanism, such as lateral diffusion in the plane of the membrane that allows them to come together near enough for integumentary contact.

Antibody-antigen interactions are widely studied biomolecular interactions to establish antibody specificity. The binding of the antibody to FcR may result in antibody-dependent cellular cytotoxicity, and interactions with a variety of human FcR are generally studied.

QSense QCM-D is utilized in this context to investigate protein-protein and protein-DNA interactions, as well as antibody-antigen interactions. It is also sensitive to conformational changes in the tertiary structure of proteins caused by small compound binding and can be used to optimize drug compounds and screening compound interactions with cells and protein drug targets.

The interference pattern of light reflected from two surfaces is used in BLI. The wavelength shift is the readout, and it is impacted by changes in biomolecular interactions. In surface plasmon resonance (SPR), the ligand is bonded to the sensor surface, which is in contact with a microfluidic device containing the analyte.

Biomolecular interactions use single-use fiberoptic biosensors (FOBS) instead of sensor chips, and there is no fluid flow; instead, the sensor tips are introduced directly to the sample on a well-plate. Similar to SPR, the ligand is bound to the sensor tip in BLI, and the analyte for the interaction is present in the sample.

The understanding of biomolecular interactions may also be utilized to develop biosensors and detector systems that mimic biological activity and can be used to detect and diagnose diseases.

Bottom Line:

This analysis is gaining popularity in a wide range of areas, including biochemistry, biotechnology, and medicine. Hence being the focus of both basic sciences and applied research and development, the overall goal of interaction studies ranges from gaining increased knowledge and understanding of biological systems and functions to applying and using the gained knowledge in the design of pharmaceuticals.

BLI is undeniably faster and allows for more screening-type studies, while SPR may be able to shave some time off. More information: https://www.jubilantbiosys.com/