Sharks are often portrayed as the monsters of the deep or the villains in horror movies, famous for their menacing teeth and killer attack instincts. In real life, however, sharks have recently inspired scientists to make strides toward improving treatments for Alzheimer’s disease and multiple sclerosis.
Custom-made antibodies are considered ultimate weapons to cure serious illnesses. By recognizing specific structures on the surface of viruses, bacteria, or cancer cells, those antibodies can successfully be deployed in cancer diagnostics and therapy. In a new study, researchers sought to understand why shark antibodies are so much more stable than human ones, since stability is a key characteristic in their effectiveness and fabrication. The researchers hoped that if they discovered why shark antibodies are so stable, they could replicate those features and use them to optimize human antibodies for medical applications.
To unravel the mystery of why shark antibodies are so stable, researchers developed a model of the IgNAR (immunoglobulin new antigen receptor) shark antibody. Despite the fact that the molecule could not be completely crystalized, they determined the atomic structures using X-ray crystallography. From these efforts, the researchers successfully identified not one, but two reasons for the added stability: an additional salt bridge between essential amino acid chains and a large non-polar nucleus in the structural folding.
But could they apply these features to synthesized human antibodies? Yes, and with resounding success. With the enhanced stability, the new human antibodies have a higher melting point (by 10 degrees!) than that of the original molecule. This will improve the fabrication, storage, and overall effectiveness of these antibodies in the future. They will even last longer inside humans, possibly leading to direct improvements in the treatment of diseases.
This valuable research not only represents advancements in the medical field, but reminds us of how much we can still learn from sharks and their 500 million years of evolutionary history. For this and other reasons, it is critical that we continue to protect and conserve marine wildlife, such as sharks, from persistent human-caused threats such as fisheries bycatch, pollution, and climate change.