TY - JOUR
T1 - Ultrafast solvation dynamics at binding and active sites of photolyases
AU - Chang, Chih Wei
AU - Guo, Lijun
AU - Kao, Ya Ting
AU - Li, Jiang
AU - Tan, Chuang
AU - Li, Tanping
AU - Saxena, Chaitanya
AU - Liu, Zheyun
AU - Wang, Lijuan
AU - Sancar, Aziz
AU - Zhong, Dongping
PY - 2010/2/16
Y1 - 2010/2/16
N2 - Dynamic solvation at binding and active sites is critical to protein recognition and enzyme catalysis. We report here the complete characterization of ultrafast solvation dynamics at the recognition site of photoantenna molecule and at the active site of cofactor/ substrate in enzyme photolyase by examining femtosecond-resolved fluorescence dynamics and the entire emission spectra. With direct use of intrinsic antenna and cofactor chromophores, we observed the local environment relaxation on the time scales from a few picoseconds to nearly a nanosecond. Unlike conventional solvation where the Stokes shift is apparent, we observed obvious spectral shape changes with the minor, small, and large spectral shifts in three function sites. These emission profile changes directly reflect the modulation of chromophore's excited states by locally constrained protein and trapped-water collective motions. Such heterogeneous dynamics continuously tune local configurations to optimize photolyase's function through resonance energy transfer from the antenna to the cofactor for energy efficiency and then electron transfer between the cofactor and the substrate for repair of damaged DNA. Such unusual solvation and synergetic dynamics should be general in function sites of proteins.
AB - Dynamic solvation at binding and active sites is critical to protein recognition and enzyme catalysis. We report here the complete characterization of ultrafast solvation dynamics at the recognition site of photoantenna molecule and at the active site of cofactor/ substrate in enzyme photolyase by examining femtosecond-resolved fluorescence dynamics and the entire emission spectra. With direct use of intrinsic antenna and cofactor chromophores, we observed the local environment relaxation on the time scales from a few picoseconds to nearly a nanosecond. Unlike conventional solvation where the Stokes shift is apparent, we observed obvious spectral shape changes with the minor, small, and large spectral shifts in three function sites. These emission profile changes directly reflect the modulation of chromophore's excited states by locally constrained protein and trapped-water collective motions. Such heterogeneous dynamics continuously tune local configurations to optimize photolyase's function through resonance energy transfer from the antenna to the cofactor for energy efficiency and then electron transfer between the cofactor and the substrate for repair of damaged DNA. Such unusual solvation and synergetic dynamics should be general in function sites of proteins.
UR - http://www.scopus.com/inward/record.url?scp=77649260740&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77649260740&partnerID=8YFLogxK
U2 - 10.1073/pnas.1000001107
DO - 10.1073/pnas.1000001107
M3 - Article
C2 - 20133751
AN - SCOPUS:77649260740
VL - 107
SP - 2914
EP - 2919
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 7
ER -