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Researchers developed aptamers that change their binding to metal ions in strong magnetic fields. This magnetic field-induced binding modulation opens doors for new biosensing and therapeutic applications.

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Area of Science:

  • Biotechnology
  • Biophysics
  • Materials Science

Background:

  • Modulating biological processes with magnetic fields is of significant interest.
  • Aptamers offer precise molecular recognition capabilities.

Purpose of the Study:

  • To develop aptamers with magnetically-modulated binding behavior for paramagnetic metal ions.
  • To investigate the mechanisms underlying magnetic field-enhanced aptamer-metal ion interactions.

Main Methods:

  • High-magnetic-field (HM)-SELEX (Systematic Evolution of Ligands by Exponential Enrichment) method was employed.
  • Targeting cobalt ions (Co2+) under varying magnetic field strengths.
  • Molecular simulations, chemical footprinting, and mutational analysis were used to elucidate mechanisms.

Main Results:

  • Two classes of aptamers with distinct magnetically-modulated binding were identified.
  • One aptamer class showed a 2-3 fold increase in affinity with increasing magnetic field strength.
  • The second aptamer class exhibited a transition from minimal binding to significant affinity (~200 μM) at high magnetic fields (≥ 6 T).
  • Molecular simulations indicated magnetic fields induce conformational changes by enhancing electrostatic interactions and optimizing nucleotide coordination.

Conclusions:

  • The study successfully generated aptamers with magnetic field-responsive binding.
  • These aptamers can function as 'aptamer switches' controlled by external magnetic fields.
  • Potential applications include magnetic field-controlled biorecognition, biosensing, and therapeutics.