This award supports theoretical research and education with the aim to develop a physical description of the unique features of the protein shells, or capsids, of viruses that infect the archaea. These viruses are stable under environments with extremes of temperature, salinity, and acidity as might be found in geysers or oil wells. This makes them particularly important for understanding the mechanisms of self-assembly, structural integrity, and even adaptability of materials designed for use under such extreme conditions. Many archaeal viruses have extraordinary capsids with negative Gauss curvature, rendering inapplicable the existing structural classification of viruses. An important characteristic of many archaeal virus capsids is that they consist of protein-lipid composites that are unusually stable against large deformation, and under conditions of extreme acidity or salt concentration.
The PIs will study these protein shells of viruses by utilizing methods from the physics of surfaces with negative Gauss curvature, the physics of lipid bilayers, the physics of composite materials, and electrostatics of molecules in ionic solutions. Their work will result in a theory capable of explaining the physical mechanisms responsible for the "pleomorphism" exhibited uniquely by archaeal viruses. These developments may provide fascinating realizations of the long-standing problem of the statistical mechanics of the melting and shape fluctuations of two-dimensional freely suspended layers.
This interdisciplinary research project will provide training to new physical scientists interested in working on a new area of biological physics, and continued support for scientific outreach activities that include the maintenance of an open source software package for continuum modeling of viruses and other structures in soft matter biophysics, visits to local K-12 schools, and recruitment of undergraduate and high school students for undergraduate research. It will contribute to development of innovative educational activities in biological physics, in particular activities that create interaction between the physical sciences and engineering.
Nontechnical Summary
Many of the single-celled microorganisms of the archaea kingdom are found in severe environments such as hot-spring geysers, oil wells, or even beneath the bottom of the oceans. Under these extreme conditions the very physical and chemical interactions that hold molecules together are dramatically changed, so much so that the study of archea has caused speculation about the possible properties of extraterrestrial life. Despite their unparalleled robustness in such harsh environments, these organisms are susceptible to another biological threat - archaeal viruses - which have evolved to hijack the protein-synthesizing machinery of the cells they infect, and to self-assemble by means of the same extreme physical and chemical interactions that hold archaea together. This award will support research to understand how passive protein building blocks of viruses are able to assemble automatically in nature into closed shells called 'capsids,' like puzzles that can put themselves together. The PIs will achieve this goal through combining mathematical methods for describing the physics of soft biological materials and molecules with mathematical techniques developed to analyze composite materials, as often used in the design of strong and lightweight structures in aerospace, mechanical, and civil engineering. This research has the promise of transforming the way to design new synthetic materials and producing the know-how needed to create robust and adaptive in extreme physical environments. The team of investigators from physics and engineering will provide training to a new generation of scientists interested in working in a new and highly interdisciplinary area of biological physics. This award will provide support for scientific outreach activities that include the maintenance and free availability of software package for mathematical modeling of viruses and other soft biological materials, visits to local K-12 schools, and recruitment of undergraduate and high school students for undergraduate research. It will provide funds for development of innovative teaching activities in biological physics, in particular activities that create interaction between the physical sciences and engineering.
