Development and applications of the 19F magic angle spinning NMR spectroscopy for studying protein-ligand interactions

Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
Protein-ligand interactions underpin a wide range of biological processes, including enzymatic catalysis, signal transduction, immune modulation, and transcriptional regulation. A comprehensive understanding of these interactions is fundamental to drug discovery and development, as they dictate the specificity, binding affinity, and efficacy of therapeutic agents. Numerous models and methodologies have been developed to elucidate protein-ligand interactions, with ongoing advancements in high-resolution experimental techniques such as X-ray crystallography, cryo-electron microscopy, and NMR, alongside increasingly efficient computational approaches including molecular docking, molecular dynamics, and quantum mechanics-based simulations. The expanding repository of structural data on protein inhibition targets has catalyzed the integration of artificial intelligence and machine learning frameworks in drug discovery efforts, accelerating lead identification, optimization, and rational drug design. These synergistic efforts aim to decode the molecular mechanisms of protein-ligand interactions, providing valuable insights into ligand selectivity, binding kinetics, and conformational dynamics. To provide a more comprehensive review of the current state of protein-ligand research, this dissertation begins with an overview of experimental and computational techniques for studying protein-ligand interactions. It evaluates their strengths and limitations to establish the rationale for developing high-resolution methods such as 19F MAS NMR. Chapter 3 provides the theoretical foundations of MAS NMR experiments, while Chapter 4 presents an original study employing 19F MAS NMR to elucidate protein-ligand interfaces using fluorinated small molecules as reporters. A key emphasis of the study is the application of small fluorinated molecules as highly sensitive reporters in solid-state NMR, highlighting the technique's capacity to probe protein-ligand interfaces with high precision in the solid state. The research focuses on Galectin-3, a biologically significant protein involved in cell adhesion, immune regulation, and cancer progression. By developing optimized experimental protocols and advanced data processing workflows, the study demonstrates how 19F MAS NMR captures ligand-induced perturbations, maps binding interfaces, and quantifies chemical shift anisotropy parameters associated with ligand dynamics. Furthermore, two-dimensional heteronuclear correlation experiments yield high-resolution spectra, identifying key residues and revealing stereospecific binding in the complexes. These findings underscore 19F MAS NMR's unique ability to resolve dynamic and structural details, serving as a complementary method to conventional techniques for studying complex systems. In summary, this dissertation presents 19F MAS NMR as a versatile tool for investigating protein-ligand interactions, underscoring its potential for widespread adoption in structural biology, biophysics, and medicinal chemistry.
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Keywords
X-ray crystallography, Protein-ligand interactions, Molecular docking
Citation