Control of Metalloprotein Reduction Potential:  Compensation Phenomena in the Reduction Thermodynamics of Blue Copper Proteins†

Biochemistry ◽  
2003 ◽  
Vol 42 (30) ◽  
pp. 9214-9220 ◽  
Author(s):  
Gianantonio Battistuzzi ◽  
Marzia Bellei ◽  
Marco Borsari ◽  
Gerard W. Canters ◽  
Ellen de Waal ◽  
...  

FEBS Letters ◽  
1989 ◽  
Vol 253 (1-2) ◽  
pp. 99-102 ◽  
Author(s):  
B.Göran Karlsson ◽  
Roland Aasa ◽  
Bo G. Malmström ◽  
Lennart G. Lundberg




2011 ◽  
Vol 699 ◽  
pp. 231-244 ◽  
Author(s):  
M. Malarvizhi ◽  
PR. Athappan

A series of copper(II) complexes with positive reduction potential have been synthesized by anin situfashion by the reaction of a Knoevenagel condensate, salicylidenebenzoylacetone (salbenz) with 4-X-anilines and copper(II) chloride. The electronic spectra of these complexes in acetonitrile show d–d bands around 540 nm with high molar extinction coefficient (ε~1600-1800 cm-1) due to lowering of symmetry around metal center, and MLCT band around 400 nm. The EPR spectral features with four g((lines having g((>2.0 >g⊥, and a broadening of g⊥component suggest a lowered site symmetry around Cu(II) monomer. The cyclic voltammetric studies of Cu(II) complexes in CH3CN shows a positive reduction potential (Epc = 492-451 mV) with moderately high peak to peak separation (∆Ep=126-163mV). All these results are comparable with the results of natural blue copper proteins even in the absence of S-coordination, and suggest that they can mimic the functional properties of blue copper proteins. These complexes on interaction with herring sperm DNA, the intense intraligand (IL) π-π*transition around 300 nm is found to be hypochromic with a slight red shift. The hypochromism and moderate binding constant are indicative of binding of the complexes with DNA with an affinity less than the classical intercalators, due to the possible substitution of the two chlorides with the DNA base pairs and relatively bulky structure of ligand molecule. Additional evidence of DNA-Cu(II) complex interaction was obtained by CD studies. The experimental results reveal that these complexes may serve as a model for blue copper proteins and as a tool for probing the structure of DNA.





2004 ◽  
Vol 7 (11) ◽  
pp. 1188-1190 ◽  
Author(s):  
Kiyoshi Fujisawa ◽  
Koyu Fujita ◽  
Tatsuya Takahashi ◽  
Nobumasa Kitajima ◽  
Yoshihiko Moro-oka ◽  
...  


1989 ◽  
Vol 260 (1) ◽  
pp. 75-79 ◽  
Author(s):  
K A Auton ◽  
C Anthony

The terminal respiratory oxidase was solubilized from membranes of organism 4025, an obligate methylotroph. The partially purified oxidase is probably a cytochrome co. It does not oxidize amicyanin, but it oxidizes ‘azurin’ and cytochromes cH and cL. By using a complete ‘methylamine oxidase’ system reconstituted from pure methylamine dehydrogenase, purified oxidase and soluble blue copper proteins and cytochromes, it was confirmed that amicyanin is essential for methylamine oxidation; it could not be replaced by ‘azurin’ or cytochrome cH or cL. It was shown that the usual mediator between amicyanin and the oxidase is cytochrome cH, with ‘azurin’ able to replace it during growth at the high copper concentrations required for optimum growth of this unusual methylotroph.





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