scholarly journals Modulating the copper–sulfur interaction in type 1 blue copper azurin by replacing Cys112 with nonproteinogenic homocysteine

2014 ◽  
Vol 1 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Kevin M. Clark ◽  
Yang Yu ◽  
Wilfred A. van der Donk ◽  
Ninian J. Blackburn ◽  
Yi Lu

Replacement of conserved Cys112 in azurin with a nonproteinogenic amino acid homocysteine affords a type-1 copper site with decreased Cu–SCys covalency.

1986 ◽  
Vol 238 (1) ◽  
pp. 291-295 ◽  
Author(s):  
L Calabrese ◽  
M Carbonaro

The two Type 1 (blue) copper-binding sites of caeruloplasmin were spectroscopically differentiated by the kinetic analysis of the e.p.r. spectra during the redox cycle. One blue copper, with a hyperfine splitting constant (A parallel) of 6.8 mT, which was rapidly reduced, was not reoxidized by oxygen, whereas it was reoxidized by H2O2. The other blue copper (A parallel = 5.8 mT), which was reduced slowly, was rapidly reoxidized by either oxygen or H2O2. A conformational change of the Type 2 copper was concomitant with the fast reduction of Type 1 copper, whereas its reduction occurred during the slow phase. This sequence of events was reversed in the reoxidation step, that is, the Type 2 copper reappeared rapidly as the species with altered conformation and reverted to the symmetry typical of the native state in the slow phase. The specific reaction of a blue-copper site with the H2O2 can tentatively be related to the established ability of caeruloplasmin to prevent ‘oxidative’ attack of proteins and lipids.


2000 ◽  
Vol 122 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Christian Buning ◽  
Gerard W. Canters ◽  
Peter Comba ◽  
Christopher Dennison ◽  
Lars Jeuken ◽  
...  

1999 ◽  
Vol 181 (8) ◽  
pp. 2323-2329 ◽  
Author(s):  
Miguel Prudêncio ◽  
Robert R. Eady ◽  
Gary Sawers

ABSTRACT The nirA gene encoding the blue dissimilatory nitrite reductase from Alcaligenes xylosoxidans has been cloned and sequenced. To our knowledge, this is the first report of the characterization of a gene encoding a blue copper-containing nitrite reductase. The deduced amino acid sequence exhibits a high degree of similarity to other copper-containing nitrite reductases from various bacterial sources. The full-length protein included a 24-amino-acid leader peptide. The nirA gene was overexpressed inEscherichia coli and was shown to be exported to the periplasm. Purification was achieved in a single step, and analysis of the recombinant Nir enzyme revealed that cleavage of the signal peptide occurred at a position identical to that for the native enzyme isolated from A. xylosoxidans. The recombinant Nir isolated directly was blue and trimeric and, on the basis of electron paramagnetic resonance spectroscopy and metal analysis, possessed only type 1 copper centers. This type 2-depleted enzyme preparation also had a low nitrite reductase enzyme activity. Incubation of the periplasmic fraction with copper sulfate prior to purification resulted in the isolation of an enzyme with a full complement of type 1 and type 2 copper centers and a high specific activity. The kinetic properties of the recombinant enzyme were indistinguishable from those of the native nitrite reductase isolated from A. xylosoxidans. This rapid isolation procedure will greatly facilitate genetic and biochemical characterization of both wild-type and mutant derivatives of this protein.


ChemBioChem ◽  
2004 ◽  
Vol 5 (11) ◽  
pp. 1579-1581 ◽  
Author(s):  
Mark D. Harrison ◽  
Christopher Dennison

Biochemistry ◽  
2009 ◽  
Vol 48 (39) ◽  
pp. 9174-9184 ◽  
Author(s):  
Moonsung Choi ◽  
Narayanasami Sukumar ◽  
Aimin Liu ◽  
Victor L. Davidson

2007 ◽  
Vol 129 (3) ◽  
pp. 519-525 ◽  
Author(s):  
Hein J. Wijma ◽  
Iain MacPherson ◽  
Ole Farver ◽  
Elitza I. Tocheva ◽  
Israel Pecht ◽  
...  

Biochemistry ◽  
1998 ◽  
Vol 37 (26) ◽  
pp. 9570-9578 ◽  
Author(s):  
Timothy E. Machonkin ◽  
Hua H. Zhang ◽  
Britt Hedman ◽  
Keith O. Hodgson ◽  
Edward I. Solomon

2010 ◽  
Vol 132 (51) ◽  
pp. 18191-18198 ◽  
Author(s):  
Daigo Shiga ◽  
Daisuke Nakane ◽  
Tomohiko Inomata ◽  
Yasuhiro Funahashi ◽  
Hideki Masuda ◽  
...  

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