Resonance Raman studies of Escherichia coli sulfite reductase hemoprotein. 1. Siroheme vibrational modes

Biochemistry ◽  
1989 ◽  
Vol 28 (13) ◽  
pp. 5461-5471 ◽  
Author(s):  
Sanghwa Han ◽  
John F. Madden ◽  
Ronald G. Thompson ◽  
Steven H. Strauss ◽  
Lewis M. Siegel ◽  
...  
Biochemistry ◽  
1989 ◽  
Vol 28 (13) ◽  
pp. 5477-5485 ◽  
Author(s):  
Sanghwa Han ◽  
John F. Madden ◽  
Lewis M. Siegel ◽  
Thomas G. Spiro

Biochemistry ◽  
1989 ◽  
Vol 28 (13) ◽  
pp. 5471-5477 ◽  
Author(s):  
John F. Madden ◽  
Sanghwa Han ◽  
Lewis M. Siegel ◽  
Thomas G. Spiro

1993 ◽  
Vol 47 (3) ◽  
pp. 292-295 ◽  
Author(s):  
Jian Chen ◽  
Ji-Ming Hu ◽  
Zhi-San Xu ◽  
Rong-Sheng Sheng

In the present study, surface-enhanced resonance Raman scattering (SERRS) spectra of α,β,γ,δ-tetra-(4-trimethyl ammonium phenyl) porphyrin [T(4-TAP)P] were obtained. With increasing pH, the relative intensities of the bands at 890 and 1244 cm−1 decreased. These bands were attributed to γ(C-H) and δ(Cm-phenyl), respectively. The bands at 420 and 576 cm−1, which were assigned to γ(phenyl-ring), were enhanced. The molecular symmetry of T(4-TAP)P is discussed in terms of group theory. The bands at 1554 and 1496 cm−1 could be attributed to the vibrational modes of the porphyrin macrocycle; the bands at 1460, 1362, and 1330 cm−1 were assigned to ν(C-C) + δ(C-H), ν(C-N) + δ(C-H), and ν(C-N), respectively. All these bands change in band intensities, positions and widths, with the potential changing from +0.2 V to −0.2 V. It was concluded that the adsorbed porphyrins underwent partial incorporation with Ag from the electrode, and the adsorbate assumed a flat orientation on the silver electrode as well as the Ag colloid surface.


1999 ◽  
Vol 19 (1-4) ◽  
pp. 237-243
Author(s):  
Colin G. Coates ◽  
John J. McGarvey ◽  
Steven E. J. Bell ◽  
Luc Jacquet ◽  
John M. Kelly ◽  
...  

Transient resonance Raman (TR2) spectroscopy has been used to investigate the metalligand charge-transfer (MLCT) excited states of Ru(II) polypyridyl complexes inDNAand in homogeneous solution. In DNA, complexes of the type [Ru(L)2(L′)]2+ were studied, where L=2, 2’-bipyridyl (bpy), 1,4, 5, 8-tetraazaphenanthrene (tap), and L′ dipyrido [3,2:a-2′ ,3′:c]-phenazine (dppz) or 1,4,5,8,9,12-hexaazatriphenylene (HAT). For [Ru(bpy)2(HAT)]2+, the enhancement pattern of vibrational modes in the TR2 spectra attributable to reduced HAT⋅− in the triplet MLCT state suggest perturbations to the intraligand transition of HAT⋅− in the presence of DNA. Transient RR spectra for [Ru(tap)2(dppz)]2+ are indicative of formation of the species RunII(tap⋅−)(tap)(dppz) by electron transfer from DNA to the triplet MLCT state of the complex.TR2 spectra for complexes of the type, [(Ru(bpy)2)n(L)]2+ , n=1, 2 where L=a triazole bridging ligand, illustrate the use of the technique as a probe of the response of MLCT states to the electronic environment.


2009 ◽  
Vol 394 (1) ◽  
pp. 141-143 ◽  
Author(s):  
Tsuyoshi Egawa ◽  
Hyun Ju Lee ◽  
Hong Ji ◽  
Robert B. Gennis ◽  
Syun-Ru Yeh ◽  
...  

1988 ◽  
Vol 42 (5) ◽  
pp. 782-788 ◽  
Author(s):  
K. A. Britton ◽  
R. A. Dalterio ◽  
W. H. Nelson ◽  
D. Britt ◽  
J. F. Sperry

Resonance Raman spectra of the gram-negative organism, Escherichia coli, have been obtained with 222.5-, 230.6-, and 251.0-nm excitation, and the results have been compared with those reported earlier for 242.4-nm excitation. Major changes in bacterial spectra have been observed with changes in exciting wavelength. The origins of the major peaks in each spectrum have been explained primarily in terms of contributions of nucleic acid bases and aromatic amino acids. As an aid in making assignments, spectra of aromatic amino acids, nucleosides, and mixtures of the two have been obtained at each wavelength used to excite bacterial spectra. Background fluorescence has been observed to be negligible below 251 nm. Selective excitation of bacterial nucleic acid and protein components has been done with ease. Results suggest that an extension of the exciting wavelength range to 190–220 nm will allow the selective excitation of additional cell components.


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