Selective Incorporation of Nitrile-Based Infrared Probes into Proteins via Cysteine Alkylation

Abstract

The nitrile stretching vibration is increasingly used as a sensitive infrared probe of local protein environments. However, site-specific incorporation of a nitrile moiety into proteins is difficult. Here we show that various aromatic nitriles can be easily incorporated into peptides and proteins via either thiol alkylation or arylation reaction.