Differential scanning calorimetry in life science: thermodynamics, stability, molecular recognition and application in drug design

All biological phenomena depend on molecular recognition, which is either intermolecular like in ligand binding to a macromolecule or intramolecular like in protein folding. As a result, understanding the relationship between the structure of proteins and the energetics of their stability and binding with others (bio)molecules is a very interesting point in biochemistry and biotechnology. It is essential to the engineering of stable proteins and to the structure-based design of pharmaceutical ligands. The parameter generally used to characterize the stability of a system (the folded and unfolded state of the protein for example) is the equilibrium constant (K) or the free energy (deltaG(o)), which is the sum of enthalpic (deltaH(o)) and entropic (deltaS(o)) terms. These parameters are temperature dependent through the heat capacity change (deltaCp). The thermodynamic parameters deltaH(o) and deltaCp can be derived from spectroscopic experiments, using the van't Hoff method, or measured directly using calorimetry. Along with isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC) is a powerful method, less described than ITC, for measuring directly the thermodynamic parameters which characterize biomolecules. In this article, we summarize the principal thermodynamics parameters, describe the DSC approach and review some systems to which it has been applied. DSC is much used for the study of the stability and the folding of biomolecules, but it can also be applied in order to understand biomolecular interactions and can thus be an interesting technique in the process of drug design.

Breast cancer

Breast cancer remains one of the leading causes of cancer morbidity and mortality. Despite significant advances in treatment of breast cancer a substantial proportion of women affected by this disease succumb to it. Survival of patients with advanced disease, chemoresistant tumors or a suboptimal response to endocrine therapy is significantly shortened. Hence, further understanding of disease pathogenesis is required to enhance the arsenal of approaches to cure this deadly ailment. Recent advances in biochemistry, molecular cell biology and cancer research highlighted the importance of dysregulation of protein synthesis, translation, in the development and progression of tumors. This dysregulation appears to take place at an early stage of translation, called translation initiation, that is a highly controlled and rate-limiting step of the protein synthesis. In this chapter we summarize decades of knowledge accumulated in regards to the role of translation and its regulation in the development and progression of breast cancer. We then extensively discuss applications of this knowledge in diagnosis and treatment of breast cancer.