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.
Blanco-Rodríguez
Ana María
AM
School of Biological and Chemical Sciences, Queen Mary, University of London, UK.
Busby
Michael
M
Gradinaru
Cristian
C
Crane
Brian R
BR
Di Bilio
Angel J
AJ
Matousek
Pavel
P
Towrie
Michael
M
Leigh
Brian S
BS
Richards
John H
JH
Vlcek
Antonín
A
Gray
Harry B
HB
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