Role of heme propionates of myoglobin in vibrational energy relaxation

The role of heme propionates of myoglobin in vibrational energy relaxation was studied by time-resolved resonance Raman spectroscopy. The decay rates of the anti-Stokes intensities of etioheme-substituted myoglobin where the heme lacks the propionates were less than those of wild-type myoglobin, suggesting that the propionates play an important role.