Site-Directed Spin Labeling of RNA by Postsynthetic Modification of 2′-Amino Groups

Subham Saha, Anil P. Jagtap, Snorri Th Sigurdsson*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

5 Citations (Scopus)


To elucidate mechanisms that govern functions of nucleic acids, it is essential to understand their structure and dynamics. Electron paramagnetic resonance (EPR) spectroscopy is a valuable technique that is routinely used to study those aspects of nucleic acids. A prerequisite for most EPR studies of nucleic acids is incorporation of spin labels at specific sites, known as site-directed spin labeling (SDSL). There are two main strategies for SDSL through formation of covalent bonds, i.e., the phosphoramidite approach and postsynthetic spin-labeling. After describing briefly the advantages and disadvantages of these two strategies, postsynthetic labeling of 2′-amino groups in RNA is delineated. Postsynthetic labeling of 2′-amino groups in RNA using 4-isocyanato-TEMPO has long been established as a useful approach. However, this method has some drawbacks, both with regard to the spin-labeling protocol and the flexibility of the spin label itself. Recently reported isothiocyanate-substituted aromatic isoindoline-derived nitroxides can be used to quantitatively and selectively modify 2′-amino groups in RNA and do not have the drawbacks associated with 4-isocyanato-TEMPO. This chapter provides a detailed description of the postsynthetic spin-labeling methods of 2′-amino groups in RNA with a special focus on using the aromatic isothiocyanate spin labels.

Original languageEnglish
Title of host publicationMethods in Enzymology
PublisherAcademic Press Inc.
Number of pages18
Publication statusPublished - 2015

Publication series

NameMethods in Enzymology
ISSN (Print)0076-6879
ISSN (Electronic)1557-7988

Bibliographical note

Publisher Copyright:
© 2015 Elsevier Inc.

Other keywords

  • 2′-Amino RNA
  • 4-Isocyanato-TEMPO
  • Aminoxyl radical
  • EPR
  • ESR
  • Isoindoline
  • Isothiocyanate
  • Nitroxide
  • SDSL
  • Spin labeling


Dive into the research topics of 'Site-Directed Spin Labeling of RNA by Postsynthetic Modification of 2′-Amino Groups'. Together they form a unique fingerprint.

Cite this