Resonance Raman spectroscopy reaction centers

Bacterial reaction centers have also been studied extensively by resonance Raman spectroscopy. Fig. 4.7-4 (for a review, see Robert, 1990 Mattioli et al., 1991a). 

H Fujiwara, H Hayashi, M Tasumi, M Kanji, YKoyamaand (Ki) Satoh (1987) Structural studies on a photosystem II reaction center complex consisting ofD-1 and D-2 polypeptides and cytochrome b-559 by resonance Raman spectroscopy and high-performance liquid chromatography. Chem Lett 10 2005-2008 GE Bialek-Bylka, T Tomo, (Ki) Satoh and Y Koyama (1995) 15-cis-carotene found in the reaction center of spinach photosystem II. FEES Lett 363 137-140... 

The first common step in AdoCbl-dependent readions is homolytic cleavage of the cobalt-carbon bond to generate a radical pair, cob(ii)alamin and the carbon-centered dAdo radical (Scheme 19.3). This reaction experiences a 10 -fold rate enhancement in B12 enzymes [14, 15] in the presence of substrate, and the mechanism for this rate acceleration has been the subject of extensive scrutiny. Thus, in methylmalonyl-CoA mutase and in glutamate mutase, little if any destabilization of the cobalt-carbon bond is observed in the reactant state, as revealed by resonance Raman spectroscopy [16, 17], and the intrinsic substrate binding is utilized to labilize the bond. In contrast, approximately half of the destabilization of the cobalt-carbon bond in diol dehydratase is expressed in the reactant state. This re-... 

Nanba O and Satoh K (1987) Isolation of a Photosystem II reaction center consisting of D1 and D2 polypeptides and cytochrome b5S9. Proc Natl Acad Sd USA 84 109-112 Noguchi T, Hayashi H, Tasumi M and Atkinson GH (1991) Solvent effects on the Ug stretching mode in the 2 Ag-excited state of )3-carotene and two derivatives picosecond time-resolved resonance Raman spectroscopy. J Phys Chem 95 3167-3172... 

Zhou Q, Robert B and Lutz M (1987) Intergeneric stmctural variability of the primary donor of photosynthetic bacteria Resonance Raman spectroscopy of reaction centers from two Rhodospirillum and Rhodobacter species. Biochim Biophys Acta 890 368-376... 

Lutz M, Kleo J and Reiss-Husson F (1976) Resonance Raman scattering of bacteriochlorophyll, bacteriopheophytin and spheroidene in reaction centers of Rhodopseudomonas spheroides. Biochem Biophys Res Comm 69 711-717 Lutz M, Chinsky L and Turpin PY (1982) Triplet states of carotenoids bound to reaction centers ofphotosynthetic bacteria Time-resolved resonance Raman spectroscopy. Photochem Photobiol 36 503-515... 

F. Resonance Raman Spectroscopy on Isotopically-Labeled Carotenoids Incorporated into Rb. sphaeroides R-26 Reaction Centers... 

The first topic to be dealt with in this article dates back to the early days of pulse radiolysis and is concerned with intermediates generated from organic nitro and nitroso compounds in some elementary redox processes. This will be followed by a presentation of some most recent results on aminyl radicals derived from amino acids, exemplifying the diversity of possible reactions of a seemingly simple type of radicals. The third example on aniline and aniline radicals aims to demonstrate the potential of time-resolved resonance Raman spectroscopy. A common message of all these studies on N-centered radicals hints at the importance of acid/base properties of radicals. The aniline system, in particular, also draws attention to spin and charge distribution, and possible implications to the chemistry of radical species. 

Picosecond Resonance Raman Spectroscopy of Rhodobacter sphaeroides Reaction Centers... 

Recently we improved the reaction center isolation procedure - A purified preparation still containing the H subunit, and displaying a stable photochemical activity, was obtained - In this article we will compare some functional properties of this reaction center preparation with reference to Rhodopseudomonas viridis and Rhodobacter sphaeroides. Similarities are found with the former at the level of the acceptor quinone complex the structure of the primary donor in both the reduced and oxidized states, as determined by Fourier transform resonance Raman spectroscopy, resembles the latter. 

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