Azidobupramine, an Antidepressant-Derived Bifunctional Neurotransmitter Transporter Ligand Allowing Covalent Labeling and Attachment of Fluorophores

PLoS One. 2016 Feb 10;11(2):e0148608. doi: 10.1371/journal.pone.0148608. eCollection 2016.

Abstract

The aim of this study was to design, synthesize and validate a multifunctional antidepressant probe that is modified at two distinct positions. The purpose of these modifications was to allow covalent linkage of the probe to interaction partners, and decoration of probe-target complexes with fluorescent reporter molecules. The strategy for the design of such a probe (i.e., azidobupramine) was guided by the need for the introduction of additional functional groups, conveying the required properties while keeping the additional moieties as small as possible. This should minimize the risk of changing antidepressant-like properties of the new probe azidobupramine. To control for this, we evaluated the binding parameters of azidobupramine to known target sites such as the transporters for serotonin (SERT), norepinephrine (NET), and dopamine (DAT). The binding affinities of azidobupramine to SERT, NET, and DAT were in the range of structurally related and clinically active antidepressants. Furthermore, we successfully visualized azidobupramine-SERT complexes not only in SERT-enriched protein material but also in living cells stably overexpressing SERT. To our knowledge, azidobupramine is the first structural analogue of a tricyclic antidepressant that can be covalently linked to target structures and further attached to reporter molecules while preserving antidepressant-like properties and avoiding radioactive isotopes.

MeSH terms

  • Amines / chemistry
  • Antidepressive Agents, Tricyclic / chemical synthesis
  • Antidepressive Agents, Tricyclic / chemistry*
  • Azepines / chemical synthesis
  • Azepines / chemistry*
  • Binding Sites
  • Cell Line
  • Dopamine / metabolism
  • Dopamine Plasma Membrane Transport Proteins / chemistry
  • Dopamine Plasma Membrane Transport Proteins / metabolism*
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • Gene Expression
  • Humans
  • Kinetics
  • Ligands
  • Molecular Probes / chemical synthesis
  • Molecular Probes / chemistry*
  • Norepinephrine / metabolism
  • Norepinephrine Plasma Membrane Transport Proteins / chemistry
  • Norepinephrine Plasma Membrane Transport Proteins / metabolism*
  • Protein Binding
  • Serotonin / metabolism
  • Serotonin Plasma Membrane Transport Proteins / chemistry
  • Serotonin Plasma Membrane Transport Proteins / metabolism*

Substances

  • Amines
  • Antidepressive Agents, Tricyclic
  • Azepines
  • Dopamine Plasma Membrane Transport Proteins
  • Fluorescent Dyes
  • Ligands
  • Molecular Probes
  • Norepinephrine Plasma Membrane Transport Proteins
  • SLC6A2 protein, human
  • SLC6A4 protein, human
  • Serotonin Plasma Membrane Transport Proteins
  • Serotonin
  • Dopamine
  • Norepinephrine

Grants and funding

The authors have no support or funding to report.