Slow Solvent Relaxation Dynamics of Nanometer Sized Reverse Micellar Systems Through Tryptophan Metabolite, Kynurenine

Authors

  • Surajit Rakshit,

    1. Unit for Nano Science & Technology, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098, India
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  • Nirmal Goswami,

    1. Unit for Nano Science & Technology, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098, India
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  • Samir Kumar Pal

    Corresponding author
      Corresponding Author email: skpal@bose.res.in (Samir Kumar Pal)
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Corresponding Author email: skpal@bose.res.in (Samir Kumar Pal)

Abstract

Exploration of environmental dynamics using intrinsic biological probe tryptophan is very important; however, it suffers from various difficulties. An alternative probe, kynurenine (KN), has been found to be an efficient probe for the ultrafast dynamics in the biological environment (Goswami et al., [2010] J. Phys. Chem. B., 114, 15236–15243). In the present study, we have investigated the efficacy of KN for the exploration of relatively slower dynamics of biologically relevant environments. A detailed investigation involving UV–Vis, steady-state/time-resolved fluorescence spectroscopy and Förster resonance energy transfer (FRET) studies on KN compared to a well-known solvation probe, H33258, a DNA-minor groove binder in a model nonionic reverse micelle reveals that ultrafast internal conversion associated with the hydrogen-bonding dynamics masks KN to become a dynamical reporter of the immediate environments of the probe.

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