Probing the reaction coordinate for ligand binding in hemoglobin using ultrafast transient Raman spectroscopy
© 1893 SPIE. Transient picosecond Raman spectroscopy is capable of differentiating vibrational relaxation from conformational changes by comparing the Stokes and anti-Stokes dynamics. We report pump-probe picosecond Raman experiments on oxy-and deoxyhemoglobin (oxyHb and deoxyHb, respectively) using 8 ps 532 nm pump pulses and 8 ps 355 nm probe pulses. Heme-to-protein vibrational cooling has been directly observed in deoxyHb for the first time, and the deconvolved cooling time constant is measured to be 2-5 ps.1-2 By applying our mode-specific Stokes and anti-Stokes technique to oxyHb, we find that any geminate recombination of photodeligated O2 must occur in either less than two picoseconds or longer than a nanosecond.
Publication Source (Journal or Book title)
Proceedings of SPIE - The International Society for Optical Engineering
Zhu, H., Lingle, R., Xu, X., & Hopkins, J. (1993). Probing the reaction coordinate for ligand binding in hemoglobin using ultrafast transient Raman spectroscopy. Proceedings of SPIE - The International Society for Optical Engineering, 1890, 123-126. https://doi.org/10.1117/12.145251.full