Structure and Dynamics of Protein Assemblies by MAS NMR

Magic angle spinning (MAS) NMR is a unique and powerful tool for structural and dynamic characterization of proteins. We have a particular focus on viral proteins including HIV and SARS-CoV-2 associated proteins and seek to understand how these viruses mature and evade the defenses of the immune system.

• Structural basis of HIV-1 maturation inhibitor binding and activity
• Atomic-Resolution Structure of SARS-CoV-2 Nucleocapsid Protein N-Terminal Domain
• Magic-angle-spinning NMR structure of the kinesin-1 motor domain assembled with microtubules reveals the elusive neck linker orientation
• Atomic-resolution structure of HIV-1 capsid tubes by magic-angle spinning NMR
• Dynamic regulation of HIV-1 capsid interaction with the restriction factor TRIM5α identified by magic-angle spinning NMR and molecular dynamics simulations
• Quenching protein dynamics interferes with HIV capsid maturation

Catalysis, Surface Chemistry, and Nanomaterials by MAS NMR

Solid state NMR is a valuable tool for the characterization of products and mechanisms of catalysis, catalytic supports (meso- and microporous materials including zeolites, alumina, and other metal oxides), and surface chemistry of nanomaterials. These insoluble systems are not readily amenable to characterization with other analytical techniques.

• A two-stage strategy for upcycling chlorine-contaminated plastic waste
• Tuning the reactivity of carbon surfaces with oxygen-containing functional groups
• Attachment Chemistry of 4-Fluorophenylboronic Acid on TiO2 and Al2O3 Nanoparticles
• Electronic modulation of metal-support interactions improves polypropylene hydrogenolysis over ruthenium catalysts
• Single pot catalyst strategy to branched products via adhesive isomerization and hydrocracking of polyethylene over platinum tungstated zirconia

¹⁹F NMR Methods Development

¹⁹F is a particularly powerful nucleus for the study of proteins, pharmaceuticals, and polymers. It is 100% natural abundant and its gyromagnetic ratio and hence sensitivity is 85% of ¹H. Fluorine does not naturally occur in biological systems but can be readily incorporated into proteins and nucleic acids, allowing us to obtain background-free site specific information. Approximately 30% of pharmaceuticals on the market contain fluorine moieties, making it an excellent marker for the study of pharmaceuticals, both in low concentration formulations as well as in vivo.

• Fast  ¹⁹F Magic-Angle Spinning Nuclear Magnetic Resonance for the Structural Characterization of Active Pharmaceutical Ingredients in Blockbuster Drugs
• ¹⁹F fast MAS (60-111 kHz) dipolar and scalar based correlation spectroscopy of organic molecules and pharmaceutical formulations
• Fast ¹⁹F Magic Angle Spinning NMR Crystallography for Structural Characterization of Fluorine-Containing Pharmaceutical Compounds
• Fast Magic-Angle Spinning ¹⁹F NMR Spectroscopy of HIV-1 Capsid Protein Assemblies
• Total and Class-Specific Determination of Fluorinated Compounds in Consumer and Food Packaging Samples Using Fluorine-19 Solid-State Nuclear Magnetic Resonance Spectroscopy

Methods for Sensitivity and Resolution Enhancement in MAS NMR

One of the greatest challenges of NMR relative to other analytical methods is low sensitivity, requiring large sample amounts and long experiment times. With our collaborators at Bruker, we are pursuing several approaches to improving sensitivity as well as resolution in MAS NMR, including fast and ultrafast magic angle spinning with ¹H- and ¹⁹F-detection, dynamic nuclear polarization (DNP), and applications of CP-MAS cryoprobes.

• Competing transfer pathways in direct and indirect dynamic nuclear polarization MAS NMR experiments on HIV-1 capsid assemblies: implications for sensitivity and resolution
• Sensitivity boosts by the CPMAS CryoProbe for challenging biological assemblies
• Ultrafast  ¹H MAS NMR Crystallography for Natural Abundance Pharmaceutical Compounds
• ¹⁹F Dynamic Nuclear Polarization at Fast Magic Angle Spinning for NMR of HIV-1 Capsid Protein Assemblies
• Expanding the horizons for structural analysis of fully protonated protein assemblies by NMR spectroscopy at MAS frequencies above 100 kHz