Mechanistic Studies on Tryptophan Lyase (NosL): Identification of Cyanide as a Reaction Product. Academic Article uri icon


  • Tryptophan lyase (NosL) catalyzes the formation of 3-methylindole-2-carboxylic acid and 3-methylindole from l-tryptophan. In this paper, we provide evidence supporting a formate radical intermediate and demonstrate that cyanide is a byproduct of the NosL-catalyzed reaction with l-tryptophan. These experiments require a major revision of the NosL mechanism and uncover an unanticipated connection between NosL and HydG, the radical SAM enzyme that forms cyanide and carbon monoxide from tyrosine during the biosynthesis of the metallo-cluster of the [Fe-Fe] hydrogenase.

published proceedings

  • J Am Chem Soc

author list (cited authors)

  • Bhandari, D. M., Fedoseyenko, D., & Begley, T. P.

citation count

  • 24

complete list of authors

  • Bhandari, Dhananjay M||Fedoseyenko, Dmytro||Begley, Tadhg P

publication date

  • January 2018