Abstract
Understanding local structural dynamics is essential for elucidating protein function and drug stability. We demonstrate how ultrafast two-dimensional infrared (2D IR) spectroscopy, combined with site-specific isotope labeling, provides unprecedented residue-level insights into molecular structure and dynamics. In bacteriorhodopsin, 13C,15N-lysine labeling revealed a structured γ-turn at K159 on the cytoplasmic surface, a motif critical for proton uptake, resolved through amide-I excitonic decoupling and picosecond spectral diffusion. In the drug cocrystal S086, a novel angiotensin receptor-neprilysin inhibitor, 2D IR spectroscopy of carboxylate stretching modes distinguished between α- and ξ-crystal forms by quantifying bidentate vs. bridging Ca2+ coordination geometries. This approach further quantified intermolecular vibrational energy transfer rates and local rigidity, correlating dynamic parameters with crystalline stability. Our work establishes nonlinear 2D IR spectroscopy as a powerful, generalizable tool for mapping site-specific conformations and ultrafast dynamics in complex biological and pharmaceutical systems, bridging the gap between static structure and functional dynamics.
Biography
Jianping Wang, FRSC. He has completed his Bachelor Degree in 1987 from Tsinghua University, PhD in 1999 from Georgia Institute of Technology postdoctoral studies from University of Pennsylvania Department of Chemistry. He is currently a group leader in the Molecular Dynamics Laboratory of ICCAS. He has published more than 200 papers in reputed journals and has been serving as an Editorial Advisory Member, the Journal of Physical Chemistry B, the American Chemical Society.
