During production, purification, formulation, and storage processes, proteins are often exposed to a variety of physical and chemical stresses that can cause them to unfold, aggregate, and compromise their function.
Heat-stress, in particular, can cause massive changes to protein structure. You can see this every time you cook an egg, as the heat turns egg whites from a translucent, soluble form to a white, solid mass. This is a result of thermal denaturation and aggregation.
Interestingly, however, while some proteins denature and form irreversible aggregates upon heating — as in the case of a cooked egg white — others can fold back and resume their function upon cooling.
Evaluating the unfolding reversibility can provide researchers with useful information about their samples. Besides deep-diving into a protein’s folding kinetics and identifying optimal refolding conditions, it can address the capacity of proteins, such as biocatalysts, to withstand temperature cycles or even their stability during various handling and storage conditions.
But how can you easily evaluate the unfolding reversibility of your protein?
PR.TimeControl software — available for the Prometheus system — offers advanced protein stability testing to precisely determine the point of irreversible unfolding. It analyzes the profile of proteins in four optional experimental modes: isothermal, two-temperature cycling, incremental temperature cycling, and stepwise temperature increase.
Along with finding critical temperatures for unfolding, the PR.TimeControl software also analyzes differences in refolding kinetics. Furthermore, it correlates unfolding and aggregation behavior at those temperatures. Visual guides in the software interface make assay protocols easy to set up or customize to address specific research needs.