[1] Univ Chicago, Inst Biophys Dynam, Chicago, IL 60637 USA
[2] Univ Chicago, James Franck Inst, Chicago, IL 60637 USA
[3] Univ Chicago, Dept Phys, Chicago, IL 60637 USA
[4] Iowa State Univ, Dept Chem & Biol Engn, Ames, IA 50011 USA
[5] Iowa State Univ, Dept Genet Dev & Cell Biol, Ames, IA 50011 USA
[6] NHLBI, Cell Biol & Physiol Ctr, NIH, Bethesda, MD 20892 USA