Drs. John Orban (Professor at the University of Maryland Institute of Bioscience and Biotechnology Research (IBBR) and Department of Chemistry and Biochemistry) and Philip Bryan (Professor at IBBR and Department of Bioengineering) have recently been awarded RO1 funding from the National Institutes of Health to study how an amino acid sequences, the building blocks of proteins, fold into a 3D conformation. While it is well known that most proteins populate a single, stable native state, the phenomenon of fold switching, where protein sequences can exist at the interface between completely different folds, creates serious challenges to our understanding of how amino acid sequence encodes 3D structure. Additionally, fold switching has many implications for understanding how proteins evolve, how mutation is related to disease, and how function is annotated to sequences of unknown structure. This grant, titled “Structure and Stability of 3-Alpha vs Alpha/Beta Folds” is awarded as a competitive renewal and will extend the findings of the research collaboration that was initially established in 2002.
In the four-year funding period of this RO1 grant, the collaboration has set forth 3 major objectives to interrogate the precise mechanisms of protein folding. The first aim sets to investigate how folds migrate through short mutational paths. To accomplish this goal, the team has chosen a series of origin folds that will be switched into different context-driven, destination folds. This approach mimics the evolutionary migration of subdomains through fold space. The second aim of the project is to determine the energetics of fold switches as a function of mutation. To accomplish this, the energetics of folding of heteromorphic pairs and bi-functional proteins will be analyzed by using the thermodynamic linkage between folding and binding. The third goal aims to determine the structures of heteromorphic and bi-functional proteins by NMR spectroscopy. To accomplish this, the group will employ the state-of-the-art NMR facility at IBBR.
Dr. Orban is a recognized expert in applying high field NMR spectroscopic methods to determine novel protein structures for better understanding the complex relationship between protein sequence and structure. Dr. Bryan is recognized for advances in the understanding of protein folding and enzymology. The collaboration between the two groups brings about the ideal expertise to investigate the complex mechanisms involved in protein folding.