The role of copper in the stability of ascorbate oxidase towards denaturing agents.
The susceptibility of native, type-2 Cu-depleted and fully Cu-depleted ascorbate oxidase to thermal and chemical denaturation has been probed by differential scanning calorimetry, fluorimetry and circular dichroism. The data indicate that copper affects the stability, but not the protein conformation. The unfolding of ascorbate oxidase is characterized by a single endotherm. Calorimetric domains revealed by deconvolution are consistent with the domains identified by X-ray crystallography.
Savini
I
I
Dipartimento di Medicina Sperimentale e Scienze Biochimiche, Università di Roma, Tor Vergata, Italy.
D'Alessio
S
S
Giartosio
A
A
Morpurgo
L
L
Avigliano
L
L
D001204:Ascorbate Oxidase / Q000378:metabolism*; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D003300:Copper / Q000378:metabolism*; D004795:Enzyme Stability; D019791:Guanidine; D006146:Guanidines / Q000494:pharmacology*; D006358:Hot Temperature; D010088:Oxidoreductases / Q000378:metabolism*; D010944:Plants / Q000201:enzymology; D011487:Protein Conformation; D011489:Protein Denaturation; D013050:Spectrometry, Fluorescence
D006146:Guanidines; D003300:Copper; D010088:Oxidoreductases; D001204:Ascorbate Oxidase; D019791:Guanidine