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Updated: May 19, 2026

Visualization of Amyloid β Deposits in the Human Brain with Matrix-assisted Laser Desorption/Ionization Imaging Mass Spectrometry
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Visualization of Amyloid β Deposits in the Human Brain with Matrix-assisted Laser Desorption/Ionization Imaging Mass Spectrometry

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The metalloprotease meprin β generates amino terminal-truncated amyloid β peptide species

Jessica Bien1, Tamara Jefferson, Mirsada Causević

  • 1Institute of Pathobiochemistry, University Medical Centre of the Johannes Gutenberg University of Mainz, 55128 Mainz, Germany.

The Journal of Biological Chemistry
|August 11, 2012
PubMed

Insights

Meprin β cleaves amyloid precursor protein (APP) and generates amyloid-beta (Aβ) peptides independently of BACE1. This metalloprotease shows higher kinetic values than BACE1, suggesting a novel therapeutic target for Alzheimer disease.

Area of Science:

  • Neuroscience
  • Biochemistry
  • Molecular Biology

Background:

  • Alzheimer disease pathogenesis involves amyloid-beta (Aβ) peptide accumulation.
  • Amyloid precursor protein (APP) processing is critical for understanding Alzheimer disease.
  • Meprin β was previously shown to cleave APP, releasing N-terminal fragments.

Purpose of the Study:

  • To investigate meprin β's role in APP processing beyond N-terminal fragment generation.
  • To determine if meprin β can act as a β-secretase-like enzyme.
  • To characterize the kinetic properties of meprin β in APP cleavage.

Main Methods:

  • Identification of meprin β cleavage sites within the Aβ sequence of wild-type and Swedish mutant APP.
  • Enzymatic assays measuring kinetic values of meprin β compared to BACE1.
  • Experiments using β-secretase inhibitors and BACE knock-out cells to assess meprin β's independence.

Main Results:

  • Meprin β cleaves APP within the Aβ sequence at p1 and p2 positions.
  • This generates Aβ variants starting at the first or second amino acid residue.
  • Meprin β exhibited higher kinetic values than BACE1 for both APP forms.
  • Meprin β's APP processing activity was confirmed independently of BACE1/2.

Conclusions:

  • Meprin β possesses β-secretase-like activity, cleaving APP to produce Aβ variants.
  • Meprin β acts independently of the canonical β-secretase pathway (BACE1/2).
  • Meprin β represents a potential novel therapeutic target for Alzheimer disease due to its role in Aβ generation.

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