Nonphotochemical hole burning of the reaction center of Rhodopseudomonas viridis

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100128a031· OSTI ID:5136106

Reddy, N R.S.; Kolaczkowski, S V; Small, G J ^[1]

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1. Iowa State Univ., Ames, IA (United States)

Reddy et al. (Science, accepted) have reported persistent, nonphotochemical hole-burned (NPHB) spectra for the Q[sub y] states of the reaction center of Rhodopseudomonas viridis. The photoinduced structural transformation was shown to be highly localized on the special pair. This transformation leads to a red shift of the special pair's lowest-energy absorption band, P960, of 150 cm[sup [minus]1] and a comparable blue shift for a state at 850 nm, which, as a consequence, could be assigned as being most closely associated with the upper dimer component. Additional experimental results are presented here together with a theoretical analysis of the extent to which the NPHB spectra provide information on the contribution from the bacteriochlorophyll monomers of the special pair to the Q[sub y] states that absorb higher in energy than P960. Structured photochemical hole-burned (PHB) spectra of P960 are also presented that underscore the importance of strong electron-phonon coupling from a broad distribution of modes with a mean frequency of 30 cm[sup [minus]1] for an understanding of the P960 absorption profile. These spectra also identify the zero-phonon hole of the strongly damped special pair marker mode (145 cm[sup [minus]1]) and its associated phonon sideband structure. Calculated spectra are presented which are in good agreement with the experimental PHB spectra. 30 refs., 6 figs., 4 tabs.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5136106
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:26; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION SPECTROSCOPY
BACTERIA
CHEMICAL REACTIONS
COMPILED DATA
COUPLING
DATA
ELECTRON TRANSFER
ELECTRON-PHONON COUPLING
HOLES
INFORMATION
MICROORGANISMS
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOSYNTHETIC BACTERIA
PROTEINS
SPECTROSCOPY