1. Weihong Qiu, Luyuan Zhang, Oghaghare Okobiah, Yi Yang,
Ultrafast Solvation Dynamics of Human Serum Albumin: Correlation with Conformational Transitions and Site-Selected Recognition
Weihong Qiu, Luyuan Zhang, Oghaghare Okobiah, Yi Yang,
Lijuan Wang, Ahmed H. Zewail and Dongping Zhong
Biophysics Program
The Ohio State University

2. Tryptophan: the Most Appropriate Fluorescence Probe in Proteins
No concerns of spatial uncertainty
Allow single-residue spatial resolution
Easy incorporation in proteins with site directed mutagenesis method

3. Conformational Transitions E F N B A
Human Serum Albumin:
Remarkable Drug Delivery Machinery &
pH-Dependent Conformation Transition
Conformational Transitions E F N B A
pH Values

4. Solvation Dynamics: the Concept
Pal, S.K.; Peon, J.; Bagchi, B. and Zewail, A.H. J.Phys. Chem. B 2002, 106, 12376

5. Femtosecond Up-Conversion Apparatus

6. Human Serum Albumin: Normal Form

7. Human Serum Albumin: Fast-Migrating Form

8. Human Serum Albumin: Extended Form

9. Conformation-Dependent Solvation Dynamics

10. Femtosecond-Resolved Rotational Anisotropy
Tryptophan residue has the largest rotational freedom in N-form HSA

11. Conformational Transitions and Solvation Dynamics: the Correlation
108 ps ps ps ps ps

12. Conclusions We found the ligand-binding pocket is highly flexible.
We established the correlation between the conformational transition of HSA and the observed solvation dynamics at the ligand-binding pocket.

13. Acknowledgements Dr. Dongping Zhong Dr. Ahmed H. Zewail Luyuan Zhang
Oghaghare Okobiah
Yi Yang
Lijuan Wang
Petroleum Research Foundation
National Science Foundation