Modulating Hinge Flexibility in the APP Transmembrane Domain Alters γ-Secretase Cleavage
| Autor: | Dieter Langosch, Hannes Heinel, Christina Scharnagl, Claudia Muhle-Goll, Harald Steiner, Philipp Högel, Simon Menig, Daniel Huster, Alexander Götz, Nadine Mylonas, Frits Kamp, Burkhard Luy, Alexander Vogel, Mara Silber, Hannes Feyrer |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Circular dichroism
Flexibility (anatomy) Mutant Biophysics Hinge Disease pathogenesis Molecular Dynamics Simulation Cleavage (embryo) metabolism [Cell Membrane] Amyloid beta-Protein Precursor 03 medical and health sciences 0302 clinical medicine Protein Domains ddc:570 metabolism [Amyloid beta-Protein Precursor] medicine Proline γ secretase Amino Acid Sequence chemistry [Amyloid beta-Protein Precursor] 030304 developmental biology 0303 health sciences Chemistry Cell Membrane Articles metabolism [Amyloid Precursor Protein Secretases] Transmembrane domain medicine.anatomical_structure genetics [Amyloid beta-Protein Precursor] Mutation Proteolysis Glycine Helix Leucine Amyloid Precursor Protein Secretases 030217 neurology & neurosurgery |
| Zdroj: | Biophys J Biophysical journal 116(11), 2103-2120 (2019). doi:10.1016/j.bpj.2019.04.030 |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/j.bpj.2019.04.030 |
| Popis: | Intramembrane cleavage of the β-amyloid precursor protein C99 substrate by γ-secretase is implicated in Alzheimer’s disease pathogenesis. Biophysical data have suggested that the N-terminal part of the C99 transmembrane domain (TMD) is separated from the C-terminal cleavage domain by a di-glycine hinge. Because the flexibility of this hinge might be critical for γ-secretase cleavage, we mutated one of the glycine residues, G38, to a helix-stabilizing leucine and to a helix-distorting proline. Both mutants impaired γ-secretase cleavage and also altered its cleavage specificity. Circular dichroism, NMR, and backbone amide hydrogen/deuterium exchange measurements as well as molecular dynamics simulations showed that the mutations distinctly altered the intrinsic structural and dynamical properties of the substrate TMD. Although helix destabilization and/or unfolding was not observed at the initial e-cleavage sites of C99, subtle changes in hinge flexibility were identified that substantially affected helix bending and twisting motions in the entire TMD. These resulted in altered orientation of the distal cleavage domain relative to the N-terminal TMD part. Our data suggest that both enhancing and reducing local helix flexibility of the di-glycine hinge may decrease the occurrence of enzyme-substrate complex conformations required for normal catalysis and that hinge mobility can thus be conducive for productive substrate-enzyme interactions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|