Fluorescent stilbazolium dyes as probes of the norepinephrine transporter: Structural insights into substrate binding

James N. Wilson, Adrienne S. Brown, W. Michael Babinchak, Clark D. Ridge, Jamie D. Walls

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

We report the synthesis, binding kinetics, optical spectroscopy and predicted binding modes of a series of sterically demanding, fluorescent norepinephrine transporter (NET) ligands. A series of bulky stilbazolium dyes, including six newly synthesized compounds, were evaluated to determine the effect of extending the molecular probes' 'heads' or 'tails'. Taking advantage of the dyes' characteristic 'turn-on' emission, the kinetic binding parameters, kon and koff were determined revealing that extension of the molecules' tails is well tolerated while expansion of the head is not. Additionally, a 'headfirst' orientation appears to be preferred over a 'tail-first' binding pose. Further details of the possible binding modes were obtained from the emission spectra of the bound probes. A small range of interplanar twist angles, approximately 35° to 60°, is predicted to produce the observed emission. Docking experiments and molecular modelling support the kinetic and spectroscopic data providing structural insights into substrate binding.

Original languageEnglish (US)
Pages (from-to)8710-8719
Number of pages10
JournalOrganic and Biomolecular Chemistry
Volume10
Issue number43
DOIs
StatePublished - Nov 21 2012

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ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry

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