Structural Biology in Vivo

The structure of a protein governs its cellular activities, both physiological and pathological. However, structural characterization is often divorced from biological activity. We are developing new biochemical approaches to study protein structure in living cells. We are particularly interested in the structures of misfolded proteins, which are both diverse and enigmatic, and how they shape disease.

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Proper folding is a necessary prerequisite for a protein to execute its evolved function. Conversely, misfolded proteins can actively interfere with cellular homeostasis. Linking a protein's structure to its activity remains an ongoing effort, which has been hindered in part by reliance on structural-biology approaches that do not directly consider the protein's activity. For example, whether or not a protein forms a crystal, which is necessary for some conventional structural-biology approaches, often has little to do with its activities. Misfolded proteins, which tend to be more heterogeneous and dynamic, have been particularly difficult to study by conventional approaches. We are therefore developing new approaches to infer protein structure directly from its activity in vivo. Specifically, by mapping the sequence determinants of a specific activity, we can build high-resolution models for the structure and dynamics of the protein in its active state. We are particularly interested in applying these approaches to understand the diversity of structures formed by misfolded proteins. Recent evidence shows that a single protein can misfold into many different structures, each of which can be associated with a different disease. We aim to reveal those structures, with an ultimate goal of characterizing pathogenic species in patients for diagnostic applications.

Students and scientists working on these problems in our lab use techniques and approaches from biochemistry, genetics, and molecular biology, including molecular cloning, library construction, next-generation sequencing, recombinant protein expression and purification, microbial culture, mammalian cell culture, flow cytometry, molecular modeling, and bioinformatics.