Excited-state dynamics of structurally characterized [ReI(CO)3(phen)(HisX)]+ (X = 83, 109) Pseudomonas aeruginosa azurins in aqueous solution.
The triplet metal-to-ligand charge transfer ((3)MLCT) dynamics of two structurally characterized Re(I)(CO)(3)(phen)(HisX)-modified (phen = 1,10-phenanthroline; X = 83, 109) Pseudomonas aeruginosa azurins have been investigated by picosecond time-resolved infrared (TRIR) spectroscopy in aqueous (D(2)O) solution. The (3)MLCT relaxation dynamics exhibited by the two Re(I)-azurins are very different from those of the sensitizer [Re(I)(CO)(3)(phen)(im)](+) (im = imidazole). Whereas the Re(I)(CO)(3) intramolecular vibrational relaxation in Re(I)(CO)(3)(phen)(HisX)Az (4 ps) is similar to that of [Re(I)(CO)(3)(phen)(im)](+) (2 ps), the medium relaxation is much slower ( approximately 250 vs 9.5 ps); the 250-ps relaxation is attributable to reorientation of D(2)O molecules as well as structural reorganization of the rhenium chromophore and nearby polar amino acids in each of the modified proteins.
School of Biological and Chemical Sciences, Queen Mary, University of London, UK.
Ana María
AM
Blanco-Rodríguez
Michael
M
Busby
Cristian
C
Gradinaru
Brian R
BR
Crane
Angel J
AJ
Di Bilio
Pavel
P
Matousek
Michael
M
Towrie
Brian S
BS
Leigh
John H
JH
Richards
Antonín
A
Vlcek
Harry B
HB
Gray
D001400:Azurin / Q000737:chemistry*; D008667:Metalloproteins / Q000737:chemistry; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry; D011487:Protein Conformation; D011550:Pseudomonas aeruginosa / Q000737:chemistry; D012211:Rhenium / Q000737:chemistry*; D012996:Solutions; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry
D008667:Metalloproteins; D010455:Peptides; D010618:Phenanthrolines; D012996:Solutions; D014867:Water; D001400:Azurin; D012211:Rhenium