Structural Mechanics of Viral Shells: Stretching Continuum Models to Their Limits

Friday, February 12, 2010 - 11:00 p.m. to Saturday, February 13, 2010 - 12:00 a.m.
ChEMS Seminar

Featuring William S. Klug, Ph.D.
Associate Professor, Mechanical & Aerospace Engineering
The Henry Samueli School of Engineering and Applied Sciences
University of California, Los Angeles

Location
:  PCB 1200
Free and open to the public

Abstract:
As revealed by techniques of structural biology, the protein shells of viruses (capsids) are some of nature's most beautiful and robust examples of highly symmetric multiscale self-assembled structures.  The ability of viral capsids to respond structurally and mechanically to physical and chemical stimuli also gives them tremendous potential as components for the design of synthetic materials with adaptive properties, as has been demonstrated by the creation of virus-based nanowires. A series of recent indentation experiments using atomic force microscopy (AFM) has shown that capsids also possess impressive mechanical properties of strength and elasticity.  In this talk I will present some analytical and numerical models of viral capsids based on continuum mechanics and Ginzburg-Landau theory, and I will discuss what we've learned about (1) the elastic response and mechanical failure of viral capsids, (2) coupling of global capsid mechanical response to local protein conformational change, and (3) the role of mechanics in capsid self-assembly.  Lastly I will describe our ongoing efforts to push the limits of usefulness of continuum theory via coupled continuum-atomistic multiscale modeling of capsids and other large protein assemblies.

About the Speaker:
William Klug, Ph.D., is an associate professor in the Department of Mechanical and Aerospace Engineering in the Henry Samueli School of Engineering and Applied Sciences at UCLA. He received a B.S. degree in engineering physics from Westmont College in 1997, an M.S. degree in civil engineering from UCLA in 1999, and a Ph.D. degree from Caltech in 2003. He is the recipient of a 2007 NSF CAREER award. Klug's primary scientific background is in continuum and computational modeling of the mechanics of solids and structures. He has particular experience in the development of numerical methods for modeling thin beam- and shell-like structures, and in the application of those methods to multi-physics problems in biology, from the macroscale to the nanoscale.  Some of his current topics of study include mechanics and assembly of viruses, mechanics of biomembranes, mechanics of motor-driven semiflexible cytoskeletal networks, and electromechanics of the heart.