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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.51A [2012] >
IJC-A Vol.51A(01-02) [January-February 2012] >
| Title: | Conformational properties of the bis-μ-(thiolato) dicopper center in cytochrome c oxidase |
| Authors: | Rajbongshi, Jitumani
Ghosh, Manas Kumar
Sanghamitra, Nusrat J M
Gupta, Sayan
Mazumdar, Shyamalava |
| Keywords: | Bioinorganic chemistry
Electron transfer proteins
Cytochrome c oxidase
Time-resolved fluorescence
Protein electrochemistry
Conformational changes
Dinuclear copper
Copper |
| Issue Date: | Jan-2012 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | The novel bis-μ(thiolato) dicopper center
(CuA) forms the electron entry site in the respiratory enzyme, cytochrome c
oxidase. While most of the electron transfer copper proteins consist of a
mono-nuclear copper center, the presence of a dinuclear copper in cytochrome c
oxidase has attracted immense interest. The CuA center from the mesophilic
organism,
P. denitrificans (PdCuA) and from the
thermophilic organism T. thermophilus (TtCuA)
have very similar spectroscopic and electronic properties, albeit the stability
of the two proteins are significantly different from each other. This dinuclear
copper center undergoes interesting conformational change induced by change in
the pH of the solution, which involves equilibrium conversion of the
purple ‘charge-delocalized’ form to a ‘valance-trapped’ form of the metal
center. The pH dependent conformational changes in the PdCuA and TtCuA
show different pKa values indicating involvement of different
amino acids in the process. The conformation change near the dinuclear center
in the mesophilic protein PdCuA is extremely fast while that in the
thermophilic protein TtCuA is very slow. The results of recent studies on the
conformational properties of this novel metal center in the protein have been
outlined in this mini-review in the light of understanding their implications
in biology. |
| Page(s): | 83-98 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0975(Online); 0376-4710(Print) |
| Source: | IJC-A Vol.51A(01-02) [January-February 2012]
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