Project Description
To perform their multitude of functions, proteins often bring—distal in sequence—residues together and fold
into reproducible higher-order structures (HOS). Ensuring the integrity of this orientation or intentionally
modulating it through post-translational modification (PTM) are vital processes that are known to be perturbed
in cancers, neurodegenerative, and cardiovascular diseases. Characterizing how PTM alters protein HOS can
be employed to identify disease state and inform and accelerate the design of new targeted therapeutic
interventions. Thus, to improve diagnostic capabilities, drug development, and provide insight into the
fundamental mechanisms driving cellular function and disease, developing techniques capable of
characterizing all the various PTM-modulated HOSs that exist for each protein is vitally important. The
sensitivity, high-throughput nature, and low sample requirements of mass spectrometry (MS) has increasingly
led to its adoption as a tool to measure protein HOS and PTM. Unfortunately, the most employed workflow,
bottom-up proteomics, demands proteolytic digestion of the analyte and thus, it is not possible to distinguish
the proteoform from which any single peptide is derived. Therefore, bottom-up workflows report the average
conformation of all existing proteoforms and the average occupancy of all PTMs. Thus, to precisely assess the
PTM-based regulation of protein function, over the next five years, we propose to develop new technologies
that couple top-down proteomics, ion mobility spectrometry, chemical derivatization, and collision-induced
unfolding. These new methods will be developed using well characterized model protein systems prior to
application to more complex biological systems. The combination of these techniques will offer significant
insight into these critical regulatory processes. In addition to these biological insights, we anticipate that this
research proposal will generate a series of MS-based analytical techniques and an assortment of chemical
reagents that will be applicable to a wide range of protein systems.