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Purification and Aggregation of the Amyloid Precursor Protein Intracellular Domain
10:08

Purification and Aggregation of the Amyloid Precursor Protein Intracellular Domain

Published on: August 28, 2012

Dimeric structure of transmembrane domain of amyloid precursor protein in micellar environment

Kirill D Nadezhdin1, Olga V Bocharova, Eduard V Bocharov

  • 1Division of Structural Biology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Str. Miklukho-Maklaya 16/10, Moscow 117997, Russian Federation.

FEBS Letters
|May 16, 2012
PubMed

Insights

Alzheimer's disease mutations may impact amyloid precursor protein (APP) dimerization. This study reveals the atomic structure of APP's transmembrane domain dimer, crucial for understanding amyloid-beta peptide formation.

Area of Science:

  • Biochemistry
  • Neuroscience
  • Structural Biology

Background:

  • Pathogenic mutations linked to Alzheimer's disease may alter amyloid precursor protein (APP) structure and dimerization within neuron membranes.
  • Understanding APP's structural dynamics is key to elucidating the molecular mechanisms underlying amyloid-beta (Aβ) peptide generation.

Purpose of the Study:

  • To determine the dimeric structure of the APP transmembrane fragment (Gln686-Lys726) at high resolution.
  • To elucidate the dimerization mechanism of the APP transmembrane domain at an atomic level.

Main Methods:

  • High-resolution Nuclear Magnetic Resonance (NMR) spectroscopy was employed.
  • The study utilized dodecylphosphocholine (DPC) micelles to mimic the neuron membrane environment.

Main Results:

  • The membrane-spanning α-helix of APP (Lys699-Lys724) was found to self-associate into a left-handed parallel dimer.
  • Dimerization occurs via an extended heptad repeat motif (I702XXXM706XXG709XXXA713XXI716XXXI720XXI723).
  • The juxtamembrane region (Gln686-Val695) forms a nascent helix that also participates in sensing dimerization.

Conclusions:

  • This research provides the first atomic-resolution description of the APP transmembrane domain dimerization mechanism.
  • The findings are significant for understanding the initial molecular events in APP processing that lead to amyloid-beta peptide production, a hallmark of Alzheimer's disease.

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