High-Resolution NMR H/D Exchange of Human Superoxide Dismutase Inclusion Bodies Reveals Significant Native Features...

Area of Science:

• Biochemistry
• Structural Biology
• Molecular Biology

Background:

• Protein aggregation is a key factor in aging and diseases.
• Cellular protein aggregates are heterogeneous, complicating structural characterization.
• Understanding the structural basis of protein aggregation is crucial for biotechnology and disease research.

Purpose of the Study:

• To perform high-resolution structural analysis of cellular inclusion bodies (IBs) from immature human superoxide dismutase (SOD1) mutants.
• To elucidate the molecular mechanisms underlying SOD1 inclusion body formation.
• To identify aggregation-prone regions within SOD1.

Main Methods:

• NMR quenched amide hydrogen/deuterium exchange (qHDX) for structural probing.
• Fourier-transform infrared spectroscopy (FTIR) to analyze secondary structure.
• Congo red binding assays to detect amyloid-like structures.

Main Results:

• The extent of SOD1 aggregation correlates with native dimer dissociation energy and global stability.
• A conserved pattern of hydrogen/deuterium exchange protection was observed across nine diverse SOD1 mutants.
• Multiple aggregation-prone regions within SOD1 were identified.

Conclusions:

• Native-like monomer associations contribute significantly to the formation of SOD1 inclusion bodies.
• SOD1 aggregation can proceed through an ensemble of pathways.
• High-resolution techniques reveal common structural features despite mutant diversity.