Physical and chemical interactions between nitric oxide and nitroxides

Ravinder J. Singh, Neil Hogg, Hassane S. Mchaourab, B. Kalyanaraman

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The physical and chemical interactions of nitric oxide (.NO) with stable nitroxides have been studied in both aqueous and membrane environments. The ESR spectrum of 3-carbamoyl-2,2,5,5,-tetramethyl-3-pyrroline-1-yloxy (CTPO) was observed to broaden upon exposure to .NO. This effect can be explained by invoking Heisenberg spin exchange as has been previously reported for molecular oxygen. No loss of total spin was observed negating the possibility of a chemical reaction between .NO and CTPO. The extent of signal broadening was proportional to the concentration of .NO and can thus be used to monitor .NO concentration. We have used this method to observe the partitioning of .NO into model membranes. We also report the use of multiquantum ESR to detect directly the effects of .NO on the membrane bound spin label 12-doxylstearic acid. This methodology may prove useful for detecting .NO in both aqueous and lipid environments and for examining the physical properties of .NO within biological membranes.

Original languageEnglish (US)
Pages (from-to)437-441
Number of pages5
JournalBBA - General Subjects
Issue number3
StatePublished - Dec 15 1994


  • Electron spin resonance
  • Liposome
  • Nitric oxide
  • Nitroxide
  • Spin level

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'Physical and chemical interactions between nitric oxide and nitroxides'. Together they form a unique fingerprint.

Cite this