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Mechanistic understanding of molecular initiating events (MIEs) using NMR spectroscopy

Paul N Sanderson1, Wendy Simpson1, Richard Cubberley1

  • 1Unilever Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedford , MK44 1LQ , UK .

Toxicology Research
|August 10, 2018
PubMed

Insights

Nuclear Magnetic Resonance (NMR) spectroscopy effectively determines reaction rates and mechanisms for molecular initiating events (MIEs) in toxicological risk assessment. This technique aids in understanding chemical reactions crucial for predicting adverse outcomes.

Area of Science:

  • Toxicology
  • Biochemistry
  • Chemical Kinetics

Background:

  • Adverse Outcome Pathways (AOP) are key to modern toxicological risk assessment.
  • Molecular Initiating Events (MIEs) are fundamental to AOP progression.
  • Covalent reactions, like protein haptenation, are critical MIEs requiring mechanistic understanding.

Purpose of the Study:

  • To demonstrate the utility of Nuclear Magnetic Resonance (NMR) spectroscopy for assessing MIEs.
  • To provide reaction rate and mechanistic data for covalent protein modification.
  • To support early toxicological risk assessment of chemical exposures.

Main Methods:

  • Utilized model systems with electrophilic species and amine/thiol nucleophiles.
  • Simulated common reactions involved in covalent protein modification.
  • Employed NMR spectroscopy to analyze reaction kinetics and mechanisms.

Main Results:

  • NMR spectroscopy effectively provided crucial reaction rate and mechanistic information.
  • Demonstrated the technique's utility for studying MIEs involving protein modification.
  • Model systems exemplified electrophilic reactions with lysine and cysteine surrogates.

Conclusions:

  • NMR spectroscopy is a valuable tool for early MIE assessment in toxicology.
  • Understanding reaction mechanisms of covalent protein modification is vital for risk assessment.
  • This approach aids in predicting toxicities like sensitization and organ damage.

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