6533b7dafe1ef96bd126f2d5

RESEARCH PRODUCT

Dynamics and toxicity of proteins with a high homology of sequences: approach by molecular dynamics and ab-initio calculations

subject

description

The elucidation of the structure and the biological function of proteins is a major stake for its implications in the biomedical research as well as in biotechnologies. In addition, there is a glass or dynamical transition for the proteins which occurs at around 200K: it has been observed by Neutron Scattering, X-ray diffraction and Mossbauer spectroscopy for different proteins. Above the transition temperature, the biological function is activated as the protein may diffuse between conformational sub-states. The microscopic origin of this transition is still debated in spite of significant advances in recent years showing the significant role of hydration. By using all-atoms classical molecular dynamics, we simulated the glass transition in a family of seven cytotoxic proteins, the thionins. Indeed, these proteins show a high homology of sequence but a very different toxicity and the relation between this toxicity and the sequence is far to be elucidated. The purpose of this work was to understand the relations between structure, dynamics and biological function of thionins.