Redox Properties of Ruthenium Nitrosyl Porphyrin Complexes with Different Axial Ligation: Structural, Spectroelectrochemical (IR, UV−Visible, and EPR), and Theoretical Studies

2008 ◽  
Vol 47 (16) ◽  
pp. 7106-7113 ◽  
Author(s):  
Priti Singh ◽  
Atanu Kumar Das ◽  
Biprajit Sarkar ◽  
Mark Niemeyer ◽  
Federico Roncaroli ◽  
...  
Keyword(s):  
Redox Properties ◽  
Theoretical Studies ◽  
Axial Ligation ◽  
Ruthenium Nitrosyl ◽  
Uv Visible

scholarly journals Crystal structure and redox properties of a novel cyanobacterial heme protein with a His/Cys heme axial ligation and a Per-Arnt-Sim (PAS)-like domain

2017 ◽  
Vol 292 (23) ◽  
pp. 9599-9612 ◽  
Author(s):  
Taiki Motomura ◽  
Michihiro Suga ◽  
Rainer Hienerwadel ◽  
Akiko Nakagawa ◽  
Thanh-Lan Lai ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Heme Protein ◽  
Redox Properties ◽  
Axial Ligation

scholarly journals Preparation, Spectroscopic Characterization and Theoretical Studies of Transition Metal Complexes with 1-[(2-(1H-indol-3-yl)ethylimino)methyl]naphthalene-2-ol Ligand

2019 ◽  
Vol 31 (11) ◽  
pp. 2430-2438 ◽  
Author(s):  
Vian Yamin Jirjees ◽  
Veyan Taher Suleman ◽  
Abbas Ali Salih Al-Hamdani ◽  
Suzan Duraid Ahmed
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Spectroscopic Characterization ◽  
Bidentate Ligand ◽  
Spectroscopic Techniques ◽  
Theoretical Studies ◽  
Ft Ir ◽  
Uv Visible ◽  
Methyl Naphthalene

A new Schiff base [1-((2-(1H-indol-3-yl)ethylimino)methyl)naphthalene-2-ol] (HL) has been synthesized by condensing (2-hydroxy-1-naphthaldehyde) with (2-(1H-indol-3-yl)ethylamine). In turn, its transition metal complexes were prepared having the general formula; [Pt(IV)Cl2(L)2], [Re(V)Cl2(L)2]Cl and [Pd(L)2], 2K[M(II)Cl2(L)2] where M(II) = Co, Ni, Cu] are reported. Ligand as well as metal complexes are characterized by spectroscopic techniques such as FT-IR, UV-visible, 13C & 1H NMR, mass, elemental analysis. The results suggested that the ligand behaves like a bidentate ligand for all the synthesized complexes. On the other hand, theoretical studies of the ligand as well its metal complexes were conducted at gas phase using HyperChem 8.0. These metal complexes exhibited good antibacterial activity.

Thermodynamic characterization of the redox centres in a representative domain of a novel c-type multihaem cytochrome

2009 ◽  
Vol 420 (3) ◽  
pp. 485-492 ◽  
Author(s):  
Leonor Morgado ◽  
Ana P. Fernandes ◽  
Yuri Y. Londer ◽  
P. Raj Pokkuluri ◽  
Marianne Schiffer ◽  
...  
Keyword(s):  
Dominant Role ◽  
Redox Properties ◽  
Geobacter Sulfurreducens ◽  
Thermodynamic Characterization ◽  
Reduction Potentials ◽  
New Type ◽  
Uv Visible ◽  
Cytochrome C7 ◽  
The Individual

Multihaem cytochromes that could form protein “nanowires” were identified in the Geobacter sulfurreducens genome, and represent a new type of multihaem cytochrome. The sequences of these proteins, two with 12 haems (GSU1996, GSU0592) and one with 27 haems (GSU2210), suggest that they are formed with domains homologous to the trihaem cytochrome c7. Although all three haems have bis-His co-ordination in cytochromes c7, in each domain of the above polymers, the haem equivalent to haem IV has His-Met co-ordination. We previously determined the structure and measured the macroscopic redox potential of one representative domain (domain C) of a dodecahaem cytochrome (GSU1996). In the present study, the microscopic redox properties of the individual haem groups of domain C were determined using NMR and UV–visible spectroscopies. The reduction potentials of the haems for the fully reduced and protonated protein are different from each other (haem I, −106 mV; haem III, −136 mV; and haem IV, −125 mV) and are strongly modulated by redox interactions. This result is rather surprising since the His-Met co-ordinated haem IV does not have the highest potential as was expected. The polypeptide environment of each haem group and the strong haem pairwise redox interactions must play a dominant role in controlling the individual haem potentials. The strong redox interactions between the haems extend the range of their operating potentials at physiological pH (haem I, −71 mV, haem III, −146 mV and haem IV, −110 mV). Such a modulation in haem potentials is likely to have a functional significance in the metabolism of G. sulfurreducens.

scholarly journals A haloarchaeal ferredoxin electron donor that plays an essential role in nitrate assimilation

2011 ◽  
Vol 39 (6) ◽  
pp. 1844-1848 ◽  
Author(s):  
Basilio Zafrilla ◽  
Rosa María Martínez-Espinosa ◽  
María José Bonete ◽  
Julea N. Butt ◽  
David J. Richardson ◽  
...  
Keyword(s):  
Essential Role ◽  
Inorganic Nitrogen ◽  
Nitrate Assimilation ◽  
Spectroscopic Characterization ◽  
Redox Properties ◽  
Nitrite Reduction ◽  
Plant Type ◽  
Uv Visible ◽  
Nitrate And Nitrite

In the absence of ammonium, many organisms, including the halophilic archaeon Haloferax volcanii DS2 (DM3757), may assimilate inorganic nitrogen from nitrate or nitrite, using a ferredoxin-dependent assimilatory NO3−/NO2− reductase pathway. The small acidic ferredoxin Hv-Fd plays an essential role in the electron transfer cascade required for assimilatory nitrate and nitrite reduction by the cytoplasmic NarB- and NirA-type reductases respectively. UV–visible absorbance and EPR spectroscopic characterization of purified Hv-Fd demonstrate that this protein binds a single [2Fe–2S] cluster, and potentiometric titration reveals that the cluster shares similar redox properties with those present in plant-type ferredoxins.

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