Physics Commons^™

Supercharged Models Of Intrinsically Disordered Proteins And Their Utility In Sensing, Peter J. Schnatz

Dissertations, Theses, and Capstone Projects

In this thesis I show that greatly increasing the magnitude of a protein’s net charge using surface supercharging transforms that protein into a ligand-gated or counterion-gated conformational molecular switch. To demonstrate this I first modified the designed helical bundle hemoprotein H4 using simple molecular modeling, creating a highly charged protein which both unfolds reversibly at low ionic strength and undergoes the ligand-induced folding transition commonly observed in signal transduction by intrinsically disordered proteins in biology. Due to the high surface charge density, ligand binding to this protein is allosterically activated by low concentrations of divalent cations and the polyamine spermine. …

Macrophage Sensing Of Single- Walled Carbon Nanotubes Via Toll- Like Receptors, Sourav P. Mukherjee, Olesja Bondarenko, Pekka Kohonen, Fernando T. Andon, Tana Brzicova, Isabel Gessner, Sanjay Mathur, Massimo Bottini, Paolo Calligari, Lorenzo Stella, Elena Kisin, Anna Shvedova, Reija Autio, Heli Salminen-Mankonen, Ritta Lahesmaa, Bengt Fadeel

Faculty & Staff Scholarship

Carbon-based nanomaterials including carbon nanotubes (CNTs) have been shown to trigger

inflammation. However, how these materials are ‘sensed’ by immune cells is not known. Here we compared the effects of two carbon-based nanomaterials, single-walled CNTs (SWCNTs) and graphene oxide (GO), on primary human monocyte-derived macrophages. Genome-wide transcriptomics assessment was performed at sub-cytotoxic doses. Pathway analysis of the microarray data revealed pronounced effects on chemokine-encoding genes in macrophages exposed to SWCNTs, but not in response to GO, and these results were validated by multiplex array-based cytokine and chemokine profiling. Conditioned medium from SWCNT-exposed cells acted as a chemoattractant for dendritic cells. …