Modeling the transient changes in the Soret-resonant Raman intensities of hemoglobin during the R -> T transition

We have performed resonance Raman (RR) intensity calculations of the Soret- resonant Raman spectra of Ni and Zn Porphine to investigate observed core s ize intensity differences in the time-resolved Sorer-resonant Raman (RR) sp ectra of hemoglobin. It was found that the metalloporphine intensities main ly derive from the expansion of the C-alpha - C-m and C-beta - C-beta bonds in the excited state, and that the observed differences are mainly due to the larger core-sized heme having a decreased C-alpha - C-m force constant and larger excited state porphyrin ring expansion.