In this award from the Chemistry of Life Processes Program in the Chemistry Division, Dr. George I. Makhatadze, from the Rensselaer Polytechnic Institute, will investigate the effects of hydrostatic pressure on the stability of proteins and enzymes. This work is the first step in understanding quantitatively the relative contributions of changes in volumetric properties (volume and thermal expansion coefficient) on protein unfolding. Site-directed variants of model proteins (eglin c, ubiquitin, acylphosphatase) with large-to-small non-polar substitutions in the protein core will be studied using the novel method of pressure perturbation calorimetry, which allows direct measurements of volume changes upon unfolding. The results of these experiments will be combined with structural and computational methods to provide quantitative estimates of the contribution of cavity formation and non-polar hydration to volume changes upon protein unfolding.
The proposed experiments will provide the first systematic study of the detailed mechanism of the effects of hydrostatic pressure on protein stability using a combination of site-directed mutagenesis and a variety of biophysical and computational tools. It is expected that the knowledge accumulated as a result of these experiments will lay the foundation for future studies of these fundamentally important issues, with broad implications for the use of proteins and enzymes in biotechnology, including renewable energy, green catalysts, and new biomaterials. Dr. Makhatadze is actively involved in graduate and undergraduate education and curriculum development. In addition, students at all levels (high-school, undergraduate and graduate) are participating directly in both the computational and experimental aspects of all research efforts in the his laboratory.
