Ultrafast vibrational dynamics in oxy-hemoglobin studied by sub-10-fs near ultraviolet pulse laser
Atsushi Yabushita1,2*, Ying-Kuan Ko1, Takasyoshi Kobayashi1,3
1Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan
2Research Institute of Engineering, Kanagawa University, Yokohama, Japan
3Brain Science Inspired Life Support Research Center, The University of Electro-Communications, Tokyo, Japan
* Presenter:Atsushi Yabushita, email:yabushita@mail.nctu.edu.tw
Hemeproteins play important roles in living system to carry oxygen, reduce oxygen, transfer electron, and so on. The active site of hemeproteins is heme which contains iron cation at the center of its porphyrin ring. Diatomic molecules like oxygen can be bound to the iron cation at the axial sites. Despite the importance of the binding function of hemeproteins, its initial reaction mechanism is still not clarified even after they have been studied by various spectroscopy methods. In the present work, we have developed ultrashort near ultraviolet laser with pulse duration shorter than 10 fs, which enables us to observe molecular vibration in time domain up to frequency of 3000 cm-1 with time-resolution of 10 fs. Using the ultrashort NUV pulse laser, we have elucidated the vibrational dynamics in oxy-hemoglobin reflecting the rebinding kinetics of oxygen after photo-excitation.

Keywords: hemoglobin, femtosecond laser, femtochemistry, ultrafast spectroscopy