Site-Specific Protein Dynamics Probed by Ultrafast Infrared Spectroscopy of a Noncanonical Amino Acid.
J Phys Chem B
; 123(45): 9592-9597, 2019 11 14.
Article
em En
| MEDLINE
| ID: mdl-31596584
ABSTRACT
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 AppABLUF; both proteins retain the red-shift on irradiation characteristic of photoactivity. Steady state and ultrafast time resolved infrared difference measurements of the azido mode reveal site-specific information on the nature and dynamics of light driven structure change. AzPhe dynamics are thus shown to be an effective probe of BLUF domain photoactivation, revealing significant differences between the two proteins and a differential response of the two sites to chromophore excitation.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenilalanina
/
Azidas
/
Sondas Moleculares
/
Flavoproteínas
Idioma:
En
Revista:
J Phys Chem B
Assunto da revista:
QUIMICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Reino Unido