In recent years, enzymes have become widely used as the additives in laundry products for reducing the energy consumption and satisfying the customer-expected cleaning effect. Boosting the stability of these enzymes has become a crucial task in both industry and laboratory. Subtilisin savinase, as an enzyme product from Novozymes A/S, has these types of needs as well, since it is usually subjected to the auto-proteolysis issues in the aqueous solution.
The overall purpose of this project is to integratively characterize the structural properties and conformational dynamics in savinase by multiple experimental techniques. The results from these studies can indicate the structural stability of savinase. In addition, the work in this thesis will deposit several structural datasets that are derived from a variety of characterization techniques (including x-ray crystallography, hydrogen-deuterium exchange by mass spectrometry and solution nuclear magnetic resonance spectroscopy), therefore offering a rich source of structural information for the future rational design of savinase.
The thesis begins with the background knowledge of enzyme stability. In the subsequent chapter, the background of the targeted enzyme for these structural studies, savinase, is introduced. Chapter 3 briefly introduces the experimental techniques for studying the structural insights and conformational fluctuations of savinase, including x-ray crystallography, hydrogen-deuterium exchange mass spectrometry (HDX-MS), and solution nuclear magnetic resonance (NMR) spectroscopy. In the following chapter of the results, I described all the results of x-ray crystallographic, HDX-MS, and solution NMR studies. In the end, the conclusions and the future perspectives are addressed, majorly focus on the structural stability of savinase. Several relevant appendices are attached with this thesis.