Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase

The activity of the erythrocyte Cu(2),Zn(2)-superoxide dismutase (SOD1) is altered in Alzheimer's disease (AD) patients. These patients, compared to healthy subjects, exhibit low plasmatic zinc (Zn) levels in the presence of high plasmatic levels of copper (Cu). SOD1 is an antioxidant enzyme ch...

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Autores principales: Manieri, Tania M., Sensi, Stefano L., Squitti, Rosanna, Cerchiaro, Giselle
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7848637/
https://www.ncbi.nlm.nih.gov/pubmed/33553758
http://dx.doi.org/10.1016/j.heliyon.2021.e06100
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author Manieri, Tania M.
Sensi, Stefano L.
Squitti, Rosanna
Cerchiaro, Giselle
author_facet Manieri, Tania M.
Sensi, Stefano L.
Squitti, Rosanna
Cerchiaro, Giselle
author_sort Manieri, Tania M.
collection PubMed
description The activity of the erythrocyte Cu(2),Zn(2)-superoxide dismutase (SOD1) is altered in Alzheimer's disease (AD) patients. These patients, compared to healthy subjects, exhibit low plasmatic zinc (Zn) levels in the presence of high plasmatic levels of copper (Cu). SOD1 is an antioxidant enzyme characterized by the presence of two metal ions, Cu and Zn, on its active site. On the SOD1, Cu exerts a catalytic role, and Zn serves a structural function. In this study, we generated a modified SOD1 characterized by an altered capacity to complex Zn. The study investigates the metal-binding dynamics of the enzyme, estimating the stability of a SOD1 protein lacking the appropriate Zn site complexation. Our mutant SOD1 possesses a double amino acid mutation (T135S and K136E) that interferes with the correct Zn site complexation. We found that the protein mutations produce unstable Zn coordination and lower enzymatic activity even when complexed with Cu. Analysis with circular dichroism (CD) spectra on metal titration showed a considerable difference between the two Zn entries in the native dimeric enzyme, and Cu presents a simultaneous entrance in the protein. Otherwise, the mutant T135S,K136E-SOD1 exhibited Zn and Cu complexation instability, being a useful in vitro model to study the SOD1 behavior in AD patients.
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spelling pubmed-78486372021-02-04 Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase Manieri, Tania M. Sensi, Stefano L. Squitti, Rosanna Cerchiaro, Giselle Heliyon Research Article The activity of the erythrocyte Cu(2),Zn(2)-superoxide dismutase (SOD1) is altered in Alzheimer's disease (AD) patients. These patients, compared to healthy subjects, exhibit low plasmatic zinc (Zn) levels in the presence of high plasmatic levels of copper (Cu). SOD1 is an antioxidant enzyme characterized by the presence of two metal ions, Cu and Zn, on its active site. On the SOD1, Cu exerts a catalytic role, and Zn serves a structural function. In this study, we generated a modified SOD1 characterized by an altered capacity to complex Zn. The study investigates the metal-binding dynamics of the enzyme, estimating the stability of a SOD1 protein lacking the appropriate Zn site complexation. Our mutant SOD1 possesses a double amino acid mutation (T135S and K136E) that interferes with the correct Zn site complexation. We found that the protein mutations produce unstable Zn coordination and lower enzymatic activity even when complexed with Cu. Analysis with circular dichroism (CD) spectra on metal titration showed a considerable difference between the two Zn entries in the native dimeric enzyme, and Cu presents a simultaneous entrance in the protein. Otherwise, the mutant T135S,K136E-SOD1 exhibited Zn and Cu complexation instability, being a useful in vitro model to study the SOD1 behavior in AD patients. Elsevier 2021-01-28 /pmc/articles/PMC7848637/ /pubmed/33553758 http://dx.doi.org/10.1016/j.heliyon.2021.e06100 Text en © 2021 The Author(s) http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Research Article
Manieri, Tania M.
Sensi, Stefano L.
Squitti, Rosanna
Cerchiaro, Giselle
Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
title Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
title_full Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
title_fullStr Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
title_full_unstemmed Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
title_short Structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
title_sort structural effects of stabilization and complexation of a zinc-deficient superoxide dismutase
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7848637/
https://www.ncbi.nlm.nih.gov/pubmed/33553758
http://dx.doi.org/10.1016/j.heliyon.2021.e06100
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