TY  - JOUR
AU  - Haker, A.
AU  - Hendriks, J.
AU  - van Stokkum, I. H. M.
AU  - Heberle, J.
AU  - Hellingwerf, K. J.
AU  - Crielaard, W.
AU  - Gensch, T.
TI  - The two photocycles of photoactive yellow protein from Rhodobacter sphaeroides
JO  - The journal of biological chemistry
VL  - 278
SN  - 0021-9258
CY  - Bethesda, Md.
PB  - Soc.
M1  - PreJuSER-28482
SP  - 8442 - 8451
PY  - 2003
N1  - Record converted from VDB: 12.11.2012
AB  - The absorption spectrum of the photoactive yellow protein from Rhodobacter sphaeroides (R-PYP) shows two maxima, absorbing at 360 nm (R-PYP(360)) and 446 nm (R-PYP(446)), respectively. Both forms are photoactive and part of a temperature- and pH-dependent equilibrium (Haker, A., Hendriks, J., Gensch, T., Hellingwerf, K. J., and Crielaard, W. (2000) FEBS Lett. 486, 52-56). At 20 degrees C, for PYP characteristic, the 446-nm absorbance band displays a photocycle, in which the depletion of the 446-nm ground state absorption occurs in at least three phases, with time constants of <30 ns, 0.5 micros, and 17 micros. Intermediates with both blue- and red-shifted absorption maxima are transiently formed, before a blue-shifted intermediate (pB(360), lambda(max) = 360 nm) is established. The photocycle is completed with a monophasic recovery of the ground state with a time constant of 2.5 ms. At 7 degrees C these photocycle transitions are slowed down 2- to 3-fold. Upon excitation of R-PYP(360) with a UV-flash (330 +/- 50 nm) a species with a difference absorption maximum at approximately 435 nm is observed that returns to R-PYP(360) on a minute time scale. Recovery can be accelerated by a blue light flash (450 nm). R-PYP(360) and R-PYP(446) differ in their overall protein conformation, as well as in the isomerization and protonation state of the chromophore, as determined with the fluorescent polarity probe Nile Red and Fourier Transform Infrared spectroscopy, respectively.
KW  - Bacterial Proteins: chemistry
KW  - Bacterial Proteins: physiology
KW  - Models, Molecular
KW  - Photoreceptors, Microbial: chemistry
KW  - Photoreceptors, Microbial: physiology
KW  - Photosynthesis
KW  - Protein Conformation
KW  - Rhodobacter sphaeroides: physiology
KW  - Spectrometry, Fluorescence
KW  - Spectroscopy, Fourier Transform Infrared
KW  - Bacterial Proteins (NLM Chemicals)
KW  - Photoreceptors, Microbial (NLM Chemicals)
KW  - photoactive yellow protein, Bacteria (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:12496261
UR  - <Go to ISI:>//WOS:000181466800091
DO  - DOI:10.1074/jbc.M209343200
UR  - https://juser.fz-juelich.de/record/28482
ER  -