The primary events in the photoactivation of yellow protein

Abstract The first steps in the photochemistry of the photoactive yellow protein are investigated with light pulses of 200 fs duration. Transient absorption kinetics are measured in the spectral region from 430 to 550 nm at room temperature upon excitation at 400 and 464 nm. The first intermediate is an excited state which develops in 0.7 ps and has a lifetime of 3.6 ps. Stimulated emission appears red-shifted and reduced in intensity in 0.7 ps, after which it decays with the 3.6 ps lifetime. The spectrum and quantum yield of the product state are consistent with the already known red-shifted photocycle intermediate pR.

[1]  K. Hellingwerf,et al.  Thiol ester-linked p-coumaric acid as a new photoactive prosthetic group in a protein with rhodopsin-like photochemistry. , 1994, Biochemistry.

[2]  K. Hellingwerf,et al.  Evidence for trans‐cis isomerization of the p‐coumaric acid chromophore as the photochemical basis of the photocycle of photoactive yellow protein , 1996, FEBS letters.

[3]  R. Hochstrasser,et al.  EXCITED STATE DYNAMICS OF BACTERIORHODOPSIN REVEALED BY TRANSIENT STIMULATED EMISSION SPECTRA , 1996 .

[4]  A Xie,et al.  Glu46 donates a proton to the 4-hydroxycinnamate anion chromophore during the photocycle of photoactive yellow protein. , 1996, Biochemistry.

[5]  G. Tollin,et al.  Photoactive yellow protein from the purple phototrophic bacterium, Ectothiorhodospira halophila. Quantum yield of photobleaching and effects of temperature, alcohols, glycerol, and sucrose on kinetics of photobleaching and recovery. , 1989, Biophysical journal.

[6]  R. Lozier,et al.  Procedure for testing kinetic models of the photocycle of bacteriorhodopsin. , 1982, Biophysical journal.

[7]  G. Fleming,et al.  Femtosecond time-resolved fluorescence spectroscopy of bacteriorhodopsin: Direct observation of excited state dynamics in the primary step of the proton pump cycle , 1993 .

[8]  T. Meyer,et al.  Isolation and characterization of soluble cytochromes, ferredoxins and other chromophoric proteins from the halophilic phototrophic bacterium Ectothiorhodospira halophila. , 1985, Biochimica et biophysica acta.

[9]  K. Hellingwerf,et al.  Photoinduced volume change and energy storage associated with the early transformations of the photoactive yellow protein from Ectothiorhodospira halophila. , 1995, Biophysical journal.

[10]  G. Tollin,et al.  Picosecond decay kinetics and quantum yield of fluorescence of the photoactive yellow protein from the halophilic purple phototrophic bacterium, Ectothiorhodospira halophila. , 1991, Biophysical journal.

[11]  M. Boissinot,et al.  Complete chemical structure of photoactive yellow protein: novel thioester-linked 4-hydroxycinnamyl chromophore and photocycle chemistry. , 1994, Biochemistry.

[12]  T. Meyer,et al.  Measurement and global analysis of the absorbance changes in the photocycle of the photoactive yellow protein from Ectothiorhodospira halophila. , 1994, Biophysical journal.