4:00pm - 5:00pm
Boettcher Auditorium 101
Protein Folding and Interactions in the Cell
Martin Gruebele, PhD
Professor and James R. Eiszner Endowed Chair in Chemistry
University of Illinois at Urbana-Chambaign
Member, National Academy of Sciences
Abstract: Protein folding and binding energy landscapes are shallow, with minima and saddle points less than tens of kT only. That makes them susceptible to the solvation environment, and hence the power of denaturants to unfold proteins or dissociate complexes. I will showcase some examples where interactions in-cell or in vivo are altered enough from in vitro that they could be physiologically relevant: action of Hsp70 as a heat shock chaperone, folding of the enzyme PGK in different animal tissues, reduced in-cell protein-RNA binding, and association of proteins inside mammalian cells subject to osmotic modulation. These experiments reveal that crowding and sticking compete in defining the intracellular energy landscape. The in-cell regime is now becoming accessible to computational models, and I will discuss molecular dynamics studies of protein sticking and crowding in a model cytoplasm.