Project Summary
We propose to study the relationship between the structure, dynamics, and function of enzymes
by examining how changes to their conformational ensembles regulate their catalytic functions.
Understanding this relationship is critical for understanding macromolecular phenomena such
as allosteric regulation, yet it remains difficult, because the relevant conformational changes
involve a hierarchy of motions that occur across broad lengthscales (sub-Å to multi-nm) and
timescales (ps-s). Our lab is developing a new generation of structural measurements that
combine temperature perturbations with static and time-resolved X-ray crystallography, allowing
us to explore the conformational landscapes of protein molecules in detail. We aim to apply
these methods to temperature-sensitive orthologs from key enzyme families, including kinases,
proteases, and ATP-dependent chaperones, to understand how changes to their conformational
ensembles modulate their biological functions. The specific goals of our work are: (1) Use multi-
temperature X-ray crystallography, combined with traditional biochemical and biophysical
assays, to quantify the relationship between conformational states and catalytic activity. (2)
Characterize previously invisible conformational states of enzymes, including cryptic pockets
that can be targeted for drug discovery, using time-resolved temperature-jump crystallography.
(3) Continue developing new hardware and software to improve the collection and analysis of
data from multi-temperature and temperature-jump crystallography. Our research represents a
novel approach to understanding how the balance of active and inactive conformations drives
the regulation of protein function. Successful completion will yield new information about the
structure-function relationships of biologically and clinically important enzymes and provide new
opportunities for targeting them with therapeutics. We expect that similar changes to protein
conformational ensembles underlie thermal regulation and other types of allosteric regulation in
these enzyme families, and therefore we expect our results to be generally useful in
understanding allosteric regulation more broadly. Finally, our work will develop a framework for
studying the relationship between protein structure, dynamics, and function that exploits the
response of protein conformational ensembles to temperature, and we aim to democratize the
use of multi-temperature and temperature-jump crystallography as a general tool for the
structural biology community.