Probing Local Environments of Adenylate Kinase with Unnatural Amino Acids

Abstract

Unnatural amino acids (UAAs) consisting of a vibrational reporter such as a nitrile, azide, or nitro group have the potential to serve as effective, site-specific probes of local protein environments. Specifically the UAA 4-cyano-L-phenylalanine (pCNF) contains a nitrile vibrational reporter that is an effective probe of local environment due to the position and sensitivity of the nitrile symmetric stretch to local environment, in addition to the relative small size of the nitrile group. Additionally, this UAA can be site-specifically incorporated into proteins using the amber codon suppression method.