The scaffolded assemblies of protein kinases that function as a unit in responding to cellular stress constitute an important nanomachine termed the stressome. Proper function of the stressome is critical for homeostasis and is dysregulated in many human diseases including inflammation and ischemia. The stressome is not simply a collection of signaling interactions, but an actual large multi-protein complex, whose changing composition and subcellular location dictates function. Efficient response to stress also requires precise spatial and temporal coordination for activation and inactivation of proteins within the stressome. To monitor dynamic changes requires the creation of probes that recognize, report on, and possibly interdict activated proteins of stress signaling pathways. Thus, we are developing probes that not only recognize specific proteins but that discriminate between different conformational states of those proteins. These probes are currently small protein domains that we refer to as conformation specific recognition elements. A recent breakthrough has been the ability to covalently attach conformation specific recognition elements to solvent-sensitive dyes that are among the brightest dyes known, providing greatly enhanced sensitivity to examine very low abundance, endogenous signaling molecules. In addition to refining the use of small protein domains we propose using combinatorial methods to isolate small peptide and synthetic small molecule conformation-specific recognition elements for detecting active and inactive conformations of stress proteins. Protein conformation sensing probes are coupled to novel cell-penetrating peptides for delivery to living cells to image signal transduction nanomachines. Biologists, chemists, mathematicians and physical scientists are working together in the areas of biosensors, protein design, peptide and small molecule discovery, nanodevice development and delivery, computational modeling, animal models of disease and planning/oversight to create the UNC initiative in nanomedicine. Relative to human disease our primary long term goal will be in the area of ischemic cardiovascular disease but our work will impact diagnosis and treatment of many diseases. Finally, the UNC Nanomedicine Center will actively interact with other nanomedicine centers and renowned biomedical investigators for the study of biological nanomachines and their role in disease and response to therapy.
