Identification of novel S-nitrosation sites in soluble guanylyl cyclase, the nitric oxide receptor

J Proteomics. 2016 Apr 14;138:40-7. doi: 10.1016/j.jprot.2016.02.009. Epub 2016 Feb 18.


Soluble Guanylyl Cyclase (sGC) is the main receptor for nitric oxide (NO). NO activates sGC to synthesize cGMP, triggering a plethora of signals. Recently, we discovered that NO covalently modifies select sGC cysteines via a post-translational modification termed S-nitrosation or S-nitrosylation. Earlier characterization was conducted on a purified sGC treated with S-nitrosoglutathione, and identified three S-nitrosated cysteines (SNO-Cys). Here we describe a more biologically relevant mapping of sGC SNO-Cys in cells to better understand the multi-faceted interactions between SNO and sGC. Since SNO-Cys are labile during LC/MS/MS, MS analysis of nitrosation typically occurs after a biotin switch reaction, in which a SNO-Cys is converted to a biotin-Cys. Here we report the identification of ten sGC SNO-Cys in rat neonatal cardiomyocytes using an Orbitrap MS. A majority of the SNO-Cys identified is located at the solvent-exposed surface of the sGC, and half of them in the conserved catalytic domain, suggesting biological significance. These findings provide a solid basis for future studies of the regulations and functions of diverse sGC S-nitrosation events in cells.

Keywords: Biotin switch; S-nitrosation; Soluble guanylyl cyclase; Tandem mass spectrometry.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cysteine / analogs & derivatives
  • Cysteine / chemistry
  • Cysteine / metabolism
  • Myocytes, Cardiac / cytology
  • Myocytes, Cardiac / enzymology*
  • Nitric Oxide / chemistry
  • Nitric Oxide / metabolism*
  • Nitrosation
  • Rats
  • Rats, Wistar
  • S-Nitrosoglutathione / chemistry
  • S-Nitrosoglutathione / metabolism
  • S-Nitrosothiols / chemistry
  • S-Nitrosothiols / metabolism
  • Soluble Guanylyl Cyclase / chemistry
  • Soluble Guanylyl Cyclase / metabolism*


  • S-Nitrosothiols
  • Nitric Oxide
  • S-Nitrosoglutathione
  • S-nitrosocysteine
  • Soluble Guanylyl Cyclase
  • Cysteine