Jump to main content
Jump to site search

Issue 23, 2010
Previous Article Next Article

Coherent dynamics and ultrafast excited state relaxation of blue copperprotein; plastocyanin

Author affiliations

Abstract

Ultrafast transient absorption measurements in the femtosecond to picosecond time region were carried out for a blue copper protein, plastocyanin (Pc). To compare the dynamical profiles after photoexcitation upon the ligand-to-metal-charge-transfer (LMCT) band and the d–d transition band, the pump wavelength was set at wavelengths of 597 and 895 nm, respectively. The results were nearly identical, indicating that the transition from the LMCT to the lower ligand field (LF) states takes place in an ultrafast time regime of less than 40 fs. Subsequently, relaxation in the LF state occurs with a time constant of 90 fs and the system returns to the ground state with that of 250 fs. The longest time constant of 1.8 ps was attributed to the vibrational cooling in the ground state. Several wavepacket motions were observed, including Franck–Condon type motion at ∼510 nm and a Herzberg–Teller type motion at 660–720 nm. Critically damped low-frequency oscillation of ∼30 cm−1 was also observed with both excitation wavelengths with the strongest amplitude around 600 nm. This oscillation could be due to the motion of the protein that is ballistically stimulated by ultrafast relaxation.

Graphical abstract: Coherent dynamics and ultrafast excited state relaxation of blue copper protein; plastocyanin

Back to tab navigation

Article information


Submitted
15 Dec 2009
Accepted
09 Mar 2010
First published
20 Apr 2010

Phys. Chem. Chem. Phys., 2010,12, 6067-6075
Article type
Paper

Coherent dynamics and ultrafast excited state relaxation of blue copper protein; plastocyanin

Y. Nagasawa, K. Fujita, T. Katayama, Y. Ishibashi, H. Miyasaka, T. Takabe, S. Nagao and S. Hirota, Phys. Chem. Chem. Phys., 2010, 12, 6067
DOI: 10.1039/B926518J

Social activity

Search articles by author

Spotlight

Advertisements