Revealing the 3D structure of proteins
At the present time, it is still difficult and costly to obtain a representation of the three-dimensional structure of proteins. But such a representation contains important indications about their function. That is why scientists have been trying to develop computer-based methods of making predictions about the properties of certain proteins that are faster than current methods.
Bridges that stabilize proteins
In a general way, different types of interactions between different amino acids, and between these amino acids and their environment, permit stabilization of the structure of proteins. Among these interactions, we find covalent bonds, and disulfide bridges in particular. These connections form through oxidation, and they are formed between atoms of sulphur contained in two amino acids that are called cysteines. “We find disulfide bridges especially at the level of extracellular proteins, which are excreted, or at the level of membranes because that allows them to be stabilized, said Julien Becker, a doctoral candidate working under the supervision of Prof Louis Wehenkel in the Systems and Modeling research unit that is part of GIGA. “Inside the cell, the environment is fairly stable and there is not so much of a need to further stabilize proteins.” For example, disulfide bridges are found in the proteins of snake or scorpion venom, in antibodiesproduced by the immune system, in insulin - the hormone that regulates the concentration of sugar in the blood – and in many other proteins.