High hydrostatic pressure effect on proteins: Fluorescence studies

Life on Earth can survive and often thrive at pressures ranging from half atmospheric pressure to over 10 000 times atmospheric pressure. Despite this fact, the effects of pressure on biological systems remain relatively unexplored, particularly those on biological macromolecules. Fluorescence spectroscopy is a sensitive probe of the structural and chemical states of macromolecules and is the most widely available and affordable technique for the study of macromolecules under high pressure. When combined with structural techniques such as high-pressure X-ray crystallography and small-angle X-ray scattering (SAXS), fluorescence spectroscopy provides deep insights into the forces that bind proteins together and imbue them with function. In this article, we describe modern experimental techniques for high-pressure fluorescence spectroscopy along with examples of their use in the study of the protein structure-function relationship and protein unfolding under high pressure.