Inhibitor screening assay for neurexin-LRRTM adhesion protein interaction involved in synaptic maintenance and neurological disorders

Anal Biochem. 2019 Dec 15:587:113463. doi: 10.1016/j.ab.2019.113463. Epub 2019 Sep 28.

Abstract

Synaptic adhesion molecules, including presynaptic neurexins (NRXNs) and post-synaptic leucine-rich repeat transmembrane (LRRTM) proteins are important for development and maintenance of brain neuronal networks. NRXNs are probably the best characterized synaptic adhesion molecules, and one of the major presynaptic organizer proteins. The LRRTMs were found as ligands for NRXNs. Many of the synaptic adhesion proteins have been linked to neurological cognitive disorders, such as schizophrenia and autism spectrum disorders, making them targets of interest for both biological studies, and towards drug development. Therefore, we decided to develop a screening method to target the adhesion proteins, here the LRRTM-NRXN interaction, to find small molecule probes for further studies in cellular settings. To our knowledge, no potent small molecule compounds against the neuronal synaptic adhesion proteins are available. We utilized the AlphaScreen technology, and developed an assay targeting the NRXN-LRRTM2 interaction. We carried out screening of 2000 compounds and identified hits with moderate IC50-values. We also established an orthogonal in-cell Western blot assay to validate hits. This paves way for future development of specific high affinity compounds by further high throughput screening of larger compound libraries using the methods established here. The method could also be applied to screening other NRXN-ligand interactions.

Keywords: Adhesion; AlphaScreen; In-cell western blot; Inhibitor assay; LRRTM; Neurexin; Neurological disorders; Synapse.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium-Binding Proteins / antagonists & inhibitors*
  • Calcium-Binding Proteins / chemistry
  • Calcium-Binding Proteins / metabolism
  • Drosophila
  • Leucine-Rich Repeat Proteins
  • Mice
  • Models, Molecular
  • Nervous System Diseases / metabolism*
  • Neural Cell Adhesion Molecules / antagonists & inhibitors*
  • Neural Cell Adhesion Molecules / chemistry
  • Neural Cell Adhesion Molecules / metabolism
  • Proteins / antagonists & inhibitors*
  • Proteins / chemistry
  • Proteins / metabolism
  • Small Molecule Libraries / pharmacology*

Substances

  • Calcium-Binding Proteins
  • Leucine-Rich Repeat Proteins
  • Neural Cell Adhesion Molecules
  • Nrxn1 protein, mouse
  • Proteins
  • Small Molecule Libraries