This research project is aimed at understanding fundamental roles of intermolecular interactions in self-assembly and structure-function relationships in multicomponent protein systems. Specifically, the project will investigate how specific lipid-protein interactions can influence transmembrane protein structure and dynamics and how metal ion-protein interactions can trigger large scale structural changes in viruses. The project will use three viral systems: Sindbis virus, Tomato Bushy Stunt virus (TBSV), and Red Clover Necrotic Mosaic virus (RCNMV). Investigation of interactions between phospholipid bilayers and small peptides mimicking the transmembrane domain glycoprotein of enveloped virus will be carried out to define constraints placed upon membrane-spanning domains for correct integration into the bilayer and to elucidate the effects of residue-sequence mutations and specific lipid-peptide interactions on peptide transmembrane assembly and dynamics. The research will elucidate the molecular mechanism and the role of divalent metal ions in triggering large-scale structural changes in plant viruses and its effect on dynamics of viral capsids. Those questions will be addressed by nitroxide spin-labeling EPR, High Field EPR, and by using manganese ions as a spectroscopic probe for the calcium ions. The High Field EPR methods developed in the course of this project will be suitable for studies of other calcium-binding systems and for investigation of membrane-associated and transmembrane proteins.
Broader impacts: The project will enhance the EPR infrastructure for research at NCSU; the project will support further development of the state-of-the-art multifrequency EPR facility that will be available for the researchers in diverse areas of chemistry, materials and life science. The project will develop new High Field EPR methods in areas of molecular and structural biology and plant pathology through proposed collaborations. The project will also result in multi disciplinary training of students from under represented groups, especially women, in application of sophisticated biophysical techniques in virology.
