Protein Biophysics “Form is a diagram of force.” D’Arcy Thompson, On Growth and Form Understanding how proteins change conformation or transduce a biochemical signal is a central challenge. We are developing several examples.  First, we are examining protein mechanics, including adhesion protein folding and unfolding, especially at surfaces. Short Fibronectin talk Second, we are studying protein structural changes associated with nitric oxide binding at cysteine residues. Slides: "Photodynamic Release of Nitric Oxide from Nitrosothiols of Glutathione and Serum Albumin Studied by Static and Transient Absorption Spectroscopy."  Meadows, P. Y.; Bemis, J. E.; Walker, G. C. “Single Molecule Force Spectroscopy of Isolated and Aggregated Fibronectin Proteins on Negatively Charged Surfaces in Aqueous Liquids”, Langmuir, 2003, accepted. Akhremitchev, B. B.; Brown, H.; Walker, G. C. "Force Modulation Mapping of Plastic Embedded, Thin-sectioned Skeletal Muscle," Micros. Microanal., 2001, 7, 32-38. Bemis, J.; Akhremitchev, B. B.; Walker, G. C. "Single Polymer Chain Elongation by Atomic Force Microscopy," Langmuir, 1999, 15, 2799-2805. Khoshtariya, D. E.; Leecharoen, R.; Hansen, E.; Walker, G. C. “Probing Protein Hydration by Difference HO-H (HO-D) Vibrational Spectroscopy: Interfacial Percolation Network Involving Highly Polarizable Water-water Hydrogen Bonds,” J. Mol. Str., 2003, 1005, 15-36. Mohney, B. K.; Petri, E.; Uvarova, V.; Walker, G. C. "Infrared and Ultraviolet‑Circular Dichroism Spectral Studies of Thermally Induced Unfolding of Apomyoglobin," Appl. Spectr., 2000, 54 ,9-14.