TP C8: Structure elucidation, molecular degradation pathways and immunological recognition properties of the β-amyloid precursor protein APP

Description

The accumulation of extracellular plaques containing the neurotoxic 42-amino acid peptide fragment (Aβ42) of the β-amyloid precursor protein (APP), is one of the characteristics of Alzheimer's disease; however, the molecular proteolytic pathways of APP and its degradation products are still unclear. In this project the proteolytic reactions of APP and its interaction products with presenilins will be investigated chiefly by identification of Aβ-specific epitopes, using new methods of affinity mass spectrometry with Fourier-transform ion cyclotron resonance (FT-ICR-MS) as a bioanalytical toll of ultra-high sensitivity and resolution. The analysis of proteolytic pathways will be initially based on the recent elucidation of an AD plaque-specific epitope of N-Terminal Aβ, Aβ(4-10), recognised by therapeutically active antisera in transgenic AD mice, which is independent of the Aβ42 structure and neurotoxicity characteristics. Affinity-proteomics methods will then be employed to identify epitopes and degradation products of recombinant APP domains, chemically synthesized and recombinant cytosolic APP fragments and polypeptides spanning the Aβ-transmembrane sequence. These epitope structures will serve as molecular probes to produce specific antibodies and identify proteopytic APP product as possible precursors of Aβ and hitherto unknown interaction partner of APP.






The accumulation of extracellular plaques containing the neurotoxic 42-amino acid peptide fragment (Aβ42) of the β-amyloid precursor protein (APP), is one of the characteristics of Alzheimer's disease; however, the molecular proteolytic pathways of APP and its degradation products are still unclear. In this project the proteolytic reactions of APP and its interaction products with presenilins will be investigated chiefly by identification of Aβ-specific epitopes, using new methods of affinity mass spectrometry with Fourier-transform ion cyclotron resonance (FT-ICR-MS) as a bioanalytical toll of ultra-high sensitivity and resolution. The analysis of proteolytic pathways will be initially based on the recent elucidation of an AD plaque-specific epitope of N-Terminal Aβ, Aβ(4-10), recognised by therapeutically active antisera in transgenic AD mice, which is independent of the Aβ42 structure and neurotoxicity characteristics. Affinity-proteomics methods will then be employed to identify epitopes and degradation products of recombinant APP domains, chemically synthesized and recombinant cytosolic APP fragments and polypeptides spanning the Aβ-transmembrane sequence. These epitope structures will serve as molecular probes to produce specific antibodies and identify proteopytic APP product as possible precursors of Aβ and hitherto unknown interaction partner of APP.

Institutions
  • FB Chemie
Funding sources
NameProject no.DescriptionPeriod
SFB584/03SFB-TR 11no information
Further information
Period: 01.07.2003 – 30.06.2007