isoalloxazine and 4-azidophenylalanine

Real-time observation of structure changes associated with protein function remains a major challenge. Ultrafast pump-probe methods record dynamics in light activated proteins, but the assignment of spectroscopic observables to specific structure changes can be difficult. The BLUF (blue light using flavin) domain proteins are an important class of light sensing flavoprotein. Here, we incorporate the unnatural amino acid (UAA) azidophenylalanine (AzPhe) at key positions in the H-bonding environment of the isoalloxazine chromophore of two BLUF domains, namely, PixD and AppA

Topics: Amino Acid Substitution; Amino Acids; Azides; Flavins; Flavoproteins; Hydrogen Bonding; Light; Molecular Probes; Mutation; Phenylalanine; Protein Conformation; Protein Domains; Protein Structure, Tertiary; Spectrophotometry, Infrared