Soluble γ-secretase modulators selectively inhibit the production of the 42-amino acid amyloid β peptide variant and augment the production of multiple carboxy-truncated amyloid β species

Biochemistry. 2014 Feb 4;53(4):702-13. doi: 10.1021/bi401537v. Epub 2014 Jan 22.


Alzheimer's disease (AD) is characterized pathologically by an abundance of extracellular neuritic plaques composed primarily of the 42-amino acid amyloid β peptide variant (Aβ42). In the majority of familial AD (FAD) cases, e.g., those harboring mutations in presenilin 1 (PS1), there is a relative increase in the levels of Aβ42 compared to the levels of Aβ40. We previously reported the characterization of a series of aminothiazole-bridged aromates termed aryl aminothiazole γ-secretase modulators or AGSMs [Kounnas, M. Z., et al. (2010) Neuron 67, 769-780] and showed their potential for use in the treatment of FAD [Wagner, S. L., et al. (2012) Arch. Neurol. 69, 1255-1258]. Here we describe a series of GSMs with physicochemical properties improved compared to those of AGSMs. Specific heterocycle replacements of the phenyl rings in AGSMs provided potent molecules with improved aqueous solubilities. A number of these soluble γ-secretase modulators (SGSMs) potently lowered Aβ42 levels without inhibiting proteolysis of Notch or causing accumulation of amyloid precursor protein carboxy-terminal fragments, even at concentrations approximately 1000-fold greater than their IC50 values for reducing Aβ42 levels. The effects of one potent SGSM on Aβ peptide production were verified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry, showing enhanced production of a number of carboxy-truncated Aβ species. This SGSM also inhibited Aβ42 peptide production in a highly purified reconstituted γ-secretase in vitro assay system and retained the ability to modulate γ-secretase-mediated proteolysis in a stably transfected cell culture model overexpressing a human PS1 mutation validating the potential for use in FAD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / antagonists & inhibitors*
  • Amyloid beta-Peptides / biosynthesis*
  • Benzene Derivatives / chemical synthesis
  • Benzene Derivatives / chemistry
  • Benzene Derivatives / pharmacology
  • Cell Line, Tumor
  • Enzyme Assays
  • Humans
  • Imidazoles / chemical synthesis
  • Imidazoles / chemistry
  • Imidazoles / pharmacology
  • Mutation
  • Peptide Fragments / biosynthesis*
  • Presenilin-1 / genetics
  • Presenilin-1 / metabolism
  • Proteolysis
  • Receptor, Notch1 / metabolism
  • Solubility
  • Structure-Activity Relationship
  • Thiazoles / chemical synthesis
  • Thiazoles / chemistry
  • Thiazoles / pharmacology


  • Amyloid beta-Peptides
  • Benzene Derivatives
  • Imidazoles
  • Peptide Fragments
  • Presenilin-1
  • Receptor, Notch1
  • Thiazoles
  • amyloid beta-protein (1-38)
  • amyloid beta-protein (1-40)
  • amyloid beta-protein (1-42)
  • Amyloid Precursor Protein Secretases