Spectroscopy and reactivity of a photogenerated tryptophan radical in a structurally defined protein environment
Miller, J.E., Gradinaru, C., Crane, B.R., Di Bilio, A.J., Wehbi, W.A., Un, S., Winkler, J.R., Gray, H.B.(2003) J Am Chem Soc 125: 14220-14221
- PubMed: 14624538 
- DOI: https://doi.org/10.1021/ja037203i
- Primary Citation of Related Structures:  
1R1C - PubMed Abstract: 
Near-UV irradiation of structurally characterized [Re(I)(CO)3(1,10-phenanthroline)(Q107H)](W48F/Y72F/H83Q/Y108W)AzM(II) [Az = Pseudomonas aeruginosa azurin, M = Cu, Zn]/[Co(NH3)5Cl]Cl2 produces a tryptophan radical (W108*) with unprecedented kinetic stability. After rapid formation (k = 2.8 x 106 s-1), the radical persists for more than 5 h at room temperature in the folded ReAzM(II) structure. The absorption spectrum of ReAz(W108*)M(II) exhibits maxima at 512 and 536 nm. Oxidation of K4[Mo(CN)8] by ReAz(W108*)Zn(II) places the W108*/W108 reduction potential in the protein above 0.8 V vs NHE.
Organizational Affiliation: 
Beckman Institute, California Institute of Technology, CA 91125, USA.