Molecular dynamics simulation studies on the aggregation of amyloid-β peptides and their disaggregation by ultrasonic wave and infrared laser irradiation

H Okumura, SG Itoh - Molecules, 2022 - mdpi.com
Alzheimer's disease is understood to be caused by amyloid fibrils and oligomers formed by
aggregated amyloid-β (Aβ) peptides. This review article presents molecular dynamics (MD) …

State-of-the-art molecular dynamics simulation studies of RNA-dependent RNA polymerase of SARS-CoV-2

S Tanimoto, SG Itoh, H Okumura - International Journal of Molecular …, 2022 - mdpi.com
Molecular dynamics (MD) simulations are powerful theoretical methods that can reveal
biomolecular properties, such as structure, fluctuations, and ligand binding, at the level of …

Key residue for aggregation of amyloid-β peptides

SG Itoh, M Yagi-Utsumi, K Kato… - ACS Chemical …, 2022 - ACS Publications
It is known that oligomers of amyloid-β (Aβ) peptide are associated with Alzheimer's disease.
Aβ has two isoforms: Aβ40 and Aβ42. Although the difference between Aβ40 and Aβ42 is …

The double-layered structure of amyloid-β assemblage on GM1-containing membranes catalytically promotes fibrillization

M Yagi-Utsumi, SG Itoh, H Okumura… - ACS Chemical …, 2023 - ACS Publications
Alzheimer's disease (AD) is associated with progressive accumulation of amyloid-β (Aβ)
cross-β fibrils in the brain. Aβ species tightly associated with GM1 ganglioside, a …

Dissociation process of polyalanine aggregates by free electron laser irradiation

H Okumura, SG Itoh, H Zen, K Nakamura - PLoS One, 2023 - journals.plos.org
Polyalanine (polyA) disease-causative proteins with an expansion of alanine repeats can be
aggregated. Although curative treatments for polyA diseases have not been explored, the …

Structural and fluctuational difference between two ends of Aβ amyloid fibril: MD simulations predict only one end has open conformations

H Okumura, SG Itoh - Scientific reports, 2016 - nature.com
A β amyloid fibrils, which are related to Alzheimer's disease, have a cross-β structure
consisting of two β-sheets: β 1 and β 2. The A β peptides are thought to be serially arranged …

Effects of a hydrophilic/hydrophobic interface on amyloid-β peptides studied by molecular dynamics simulations and NMR experiments

SG Itoh, M Yagi-Utsumi, K Kato… - The Journal of Physical …, 2018 - ACS Publications
Oligomer formation of amyloid-β peptides (Aβ) is accelerated at a hydrophilic/hydrophobic
interface. However, details of the acceleration mechanism have not been elucidated. To …

Role of water molecules and helix structure stabilization in the laser-induced disruption of amyloid fibrils observed by nonequilibrium molecular dynamics simulations

H Okumura, SG Itoh, K Nakamura… - The Journal of Physical …, 2021 - ACS Publications
Water plays a crucial role in the formation and destruction of biomolecular structures. The
mechanism for destroying biomolecular structures was thought to be an active breaking of …

Replica-permutation molecular dynamics simulations of an amyloid-β (16–22) peptide and polyphenols

LLN Ngoc, SG Itoh, P Sompornpisut… - Chemical Physics Letters, 2020 - Elsevier
Aggregates of amyloid-β (Aβ) peptides, such as oligomers and amyloid fibrils, are related to
Alzheimer's disease. Polyphenols are known to inhibit the aggregation of Aβ peptides. We …

Why Is Arginine the Only Amino Acid That Inhibits Polyglutamine Monomers from Taking on Toxic Conformations?

S Tanimoto, H Okumura - ACS Chemical Neuroscience, 2024 - ACS Publications
Polyglutamine (polyQ) diseases are devastating neurodegenerative disorders characterized
by abnormal expansion of glutamine repeats within specific proteins. The aggregation of …