Antigen molecular recognition

We have already mentioned the application of supercomputers to biochemical simulations. Internal dynamics may play an Important role In such simulations. An example would be enzyme binding-site fluctuations that modulate reactivity or the dynamics of antigen-antibody association (11). In the specific case of diffusion-controlled processes, molecular recognition may occur because of long-range sterlc effects which are hard to assess without very expensive simulations (12.)-... 

Biosensors normally offer highly specific molecular recognition reactions like enzyme/substrate-, antigen/antibody-, DNA/DNA-, or protein-interactions [67]. Due to their specific sensing principles and set-up they are limited to special applications and boundary conditions. The limited stability and reproducibility of these devices requires higher standards of maintenance and recalibration. 

Communication requires a signal and a signal receiver. Signal receivers are termed receptors. We have seen two examples the antigen-specific receptors on B cells and the receptors on T cells which recognize Class II MHC processed antigen complexes on the surface of B cells, two more examples of molecular recognition. 

Molecular recognition is critical for fife enzymes recognize substrates, antibodies recognize antigens, receptors recognize signaling molecules, and so on. 

In fields such as biosensing, analyte binding often relies on very specific molecular recognition interactions that nature has supplied, such as antibody-antigen interactions or strands of complimentary DNA forming double hefices. Unfortunately, because versatile and highly selective receptors for TNT or other explosive molecules are not available, chemists are left to rely on less specific interactions. 

Molecular recognition in biological systems (active sites on the surfaces of macromolecule, antibody-antigen) and biological sensors (enzyme activity, biosensors). 

The immune system that is present in higher eukaryotes is a highly diverse molecular recognition system which on average consists of 10 to 10 ° different antigen binding... 

Fig. 17. Molecular recognition-dependent photochemical molecular devices. Photochemical processes such as energy transfer (ET) or photoinduced electron transfer (PeT) may be induced via association of two (or more) complementary units, each bearing a component of the device the complementary units may be as small as heterocyclic bases or as large as antigen-antibody conjugates.

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