Primary steps of the photoactive yellow protein: Isolated chromophore dynamics and protein directed function
The cycle of the photoactive yellow protein (PYP) has been extensively studied, but the dynamics of the isolated chromophore responsible for transduction is unknown. Here, we present real-time observation of the dynamics of the negatively charged chromophore and detection of intermediates along the path of trans-to-cis isomerization using femtosecond mass selection/electron detachment techniques. The results show that the role of the protein environment is not in the first step of double-bond twisting (barrier crossing) but in directing efficient conversion to the cis-structure and in impeding radical formation within the protein.
Additional Information© 2006 by The National Academy of Sciences of the USA Contributed by Ahmed H. Zewail, November 17, 2005. Published online before print January 3, 2006, 10.1073/pnas.0510015103 We thank Prof. Monique M. Martin and Drs. Agathe Espagne and D. Hern Paik for stimulating discussion; the collaborative work on solution-phase studies will be published elsewhere. This work was supported by the National Science Foundation. Author contributions: A.H.Z. designed research; I-R.L. and W.L. performed research; I-R.L. and W.L. analyzed data; and I-R.L., W.L., and A.H.Z. wrote the paper. Conflict of interest statement: No conflicts declared.
Published - LEEpnas06.pdf