New Physical Approaches to Molecular and Cellular Machines

Coordinators: David Bensimon, Robijn Bruinsma, Philip Nelson, V. Adrian Parsegian

The development of new experimental methods to manipulate and visualize single molecules has opened a new vista on the study of molecular and supramolecular devices in cells, including DNA and RNA polymerases, helicases, topoisomerases, the F1-ATPase system, gated ion channels, myosin, actin, the flagellar motor, the mitotic spindle, the Golgi apparatus, and much more. Particularly exciting have been the development of techniques sensitive enough to probe the operation of these devices inside living cells. Thus not only structure, but also function in the cellular milieu are now becoming the subject of precise quantitative measurements.

These systems have been studied individually from the biophysical perspective for many years. But the time is now ripe for a cross-cutting look at them, both in the light of the new experimental results and using contemporary theoretical ideas and simulation techniques. Moreover, the wealth of quantitative data on the physical responses of molecular and cellular machines(for example, motor velocity) to physical perturbations(for example, mechanical force) has attracted the attention of many theoretical physicists in the "soft matter" community and elsewhere.

An explicit aim of the program is to nurture the growing synergy between theoretical physicists, molecular modelers, and their experimental life-science colleagues. The theorists will gain an appreciation of current pressing problems and real-world issues, and reciprocally the experimentalists will see opportunities created by existing theoretical tools. Many of these theorists have backgrounds in subfields like nonlinear dynamics, liquid crystal and polymer physics, disordered systems, fluid mechanics, statistical mechanics of random shapes, and so on - fields that have not traditionally had much contact with molecular biophysics, but which are now offering fresh conceptual approaches.

Planned topical groups:

1) New fluorescence methods
2) Processive molecular machines, cytoskeleton and motility
3) Chromatin and DNA Packaging/Looping/Regulation
4) Physical approaches to viruses