02295nas a2200289   4500008004500000020001400045245010500059210006900164260000800233300001600241490000800257520142900265653001401694653002301708653002401731653001301755653002201768653002201790653002901812653001701841653002001858653002701878653002001905100001501925700001601940856004901956       2010                        Engldsh    a1520-610600aHydration Effects on Energy Relaxation of Ferric Cytochrome C Films after Soret-Band Photoexcitation0 aHydration Effects on Energy Relaxation of Ferric Cytochrome C Fi  cNov  a15151-151570 v1143 a<p>Protein hydration plays a critical role in protein dynamics and biological processes. Pump-probe transmission measurement has been applied to investigate the hydration effects on the energy relaxation of a heme protein ferric Cytochrome c (Cyt c) film after soret-band photoexcitation. Transient dynamics study indicates that the energy internal conversion time of similar to 300 fs is independent of hydration. The vibrationally excited electronic ground-state recovery rates show two transitions at the hydration level of h = 12.4-16.5% and 21.7-23.5%. The first transition occurs at the hydration level for the onset of an increasing ferric Cyt c flexibility while the second transition occurs at the saturated hydration level. The hydration dependence of steady-state electronic absorption spectrum results shows that the Q-band peak is nearly constant in center wavelength, but the line width surprisingly narrows with increasing hydration. For the similar to 695 nm absorbance associated with the MET80-Fe bond, the intensity increases with increasing hydration and slightly blue shifts. The 695 nm peak grows rapidly at h = 12.4% and then plateaus at h = 21.7%. This research shows that similar to 695 nm absorbance and ground-state recovery rates are sensitive to the hydration of the protein. This study will aid in understanding how hydration modulates the activity of the protein dynamics at a local level.</p>10aChemistry10acircular-dichroism10aconformation change10adynamics10aferricytochrome-c10aprotein hydration10aresolved resonance raman10aspectroscopy10aunfolded states10avibrational-relaxation10awater-molecules1 aYe, S., J.1 aMarkelz, A.  uhttps://markelz.physics.buffalo.edu/node/274