Stirpe, A. and Guzzi, R. (2006) Thermal unfolding of holo and apo pseudoazurin. Il nuovo cimento C, 29 (3). pp. 351-360. ISSN 1826-9885
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Abstract
The role of the copper ion in the thermal unfolding of pseudoazurin has been investigated by differential scanning calorimetry, optical density and fluorescence. In the presence of copper the denaturation of pseudoazurin (holo form) is irreversible and scan rate dependent. The melting temperature ranges between 60.0 and 67.3◦C, depending on the scan rate and the technique used. The DSC data analysis indicates that the denaturation pathway of the holo pseudoazurin is described by the classical Lumry-Eyring model, N ⇔ U ⇒ F. The simulation of the experimental DSC profiles according to this model has allowed the calculation of the thermodynamic and kinetic parameters related to the two steps. The destabilization of the copper active site and of the hydrophobic core precedes the global denaturation of the protein. The removal of the copper ion (apo from) significantly reduces the stability of the protein: the denaturation occurs at 41.8◦C. Moreover, the thermal unfolding of apo pseudoazurin is compatible with a two-state reversible process, N ⇔ U.
Item Type: | Article |
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Uncontrolled Keywords: | Proteins ; Dynamics and conformational changes |
Subjects: | 500 Scienze naturali e Matematica > 530 Fisica |
Depositing User: | Marina Spanti |
Date Deposited: | 19 Mar 2020 14:15 |
Last Modified: | 19 Mar 2020 14:15 |
URI: | http://eprints.bice.rm.cnr.it/id/eprint/16085 |
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