One of the quests of protein researchers is to understand how proteins behave inside cells. And since proteins come in different sizes, shapes and occupations, measurement methods that work for small, simple proteins, for example, may not work well for larger, more flexible proteins. Prof. Daniella Goldfarb explains in this interview for The Scientists’ Channel how changing the labels used to highlight proteins can bring results: She and her group replaced the commonly used small, organic spin labels, which lose their paramagnetism in the cell with ones made from the metallic element gadolinium. These do remain paramagnetic and stably attached to various points on a protein inside the cell. The researchers reinsert these proteins into cells and, using the high-field electron paramagnetic resonance (EPR) equipment that measures unpaired electron spin, they can determine the distance between pairs of such spin-labels and therefore the can detect movement between labels. This measurement reveals conformational changes and thus helps scientists uncover dynamic protein structures and actions. Among other things, Prof. Goldfarb’s research is showing that proteins may perform differently inside cells than they do in common lab solutions.
Prof. Daniella Goldfarb is the incumbent of the Erich Klieger Professorial Chair in Chemical Physics.