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Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods

Cataract formation is a slow accumulative process due to protein aggregates promoted by different factors over time. Zinc and copper ions have been reported to induce the formation of aggregates opaque to light in the human gamma D crystallin (HγD) in a concentration and temperature dependent manner...

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Autores principales: Fernández-Silva, Arline, French-Pacheco, Leidys, Rivillas-Acevedo, Lina, Amero, Carlos
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7295030/
https://www.ncbi.nlm.nih.gov/pubmed/32566392
http://dx.doi.org/10.7717/peerj.9178
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author Fernández-Silva, Arline
French-Pacheco, Leidys
Rivillas-Acevedo, Lina
Amero, Carlos
author_facet Fernández-Silva, Arline
French-Pacheco, Leidys
Rivillas-Acevedo, Lina
Amero, Carlos
author_sort Fernández-Silva, Arline
collection PubMed
description Cataract formation is a slow accumulative process due to protein aggregates promoted by different factors over time. Zinc and copper ions have been reported to induce the formation of aggregates opaque to light in the human gamma D crystallin (HγD) in a concentration and temperature dependent manner. In order to gain insight into the mechanism of metal-induced aggregation of HγD under conditions that mimic more closely the slow, accumulative process of the disease, we have studied the non-equilibrium process with the minimal metal dose that triggers HγD aggregation. Using a wide variety of biophysics techniques such as turbidimetry, dynamic light scattering, fluorescence, nuclear magnetic resonance and computational methods, we obtained information on the molecular mechanisms for the formation of aggregates. Zn(II) ions bind to different regions at the protein, probably with similar affinities. This binding induces a small conformational rearrangement within and between domains and aggregates via the formation of metal bridges without any detectable unfolded intermediates. In contrast, Cu(II)-induced aggregation includes a lag time, in which the N-terminal domain partially unfolds while the C-terminal domain and parts of the N-terminal domain remain in a native-like conformation. This partially unfolded intermediate is prone to form the high-molecular weight aggregates. Our results clearly show that different external factors can promote protein aggregation following different pathways.
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spelling pubmed-72950302020-06-20 Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods Fernández-Silva, Arline French-Pacheco, Leidys Rivillas-Acevedo, Lina Amero, Carlos PeerJ Biochemistry Cataract formation is a slow accumulative process due to protein aggregates promoted by different factors over time. Zinc and copper ions have been reported to induce the formation of aggregates opaque to light in the human gamma D crystallin (HγD) in a concentration and temperature dependent manner. In order to gain insight into the mechanism of metal-induced aggregation of HγD under conditions that mimic more closely the slow, accumulative process of the disease, we have studied the non-equilibrium process with the minimal metal dose that triggers HγD aggregation. Using a wide variety of biophysics techniques such as turbidimetry, dynamic light scattering, fluorescence, nuclear magnetic resonance and computational methods, we obtained information on the molecular mechanisms for the formation of aggregates. Zn(II) ions bind to different regions at the protein, probably with similar affinities. This binding induces a small conformational rearrangement within and between domains and aggregates via the formation of metal bridges without any detectable unfolded intermediates. In contrast, Cu(II)-induced aggregation includes a lag time, in which the N-terminal domain partially unfolds while the C-terminal domain and parts of the N-terminal domain remain in a native-like conformation. This partially unfolded intermediate is prone to form the high-molecular weight aggregates. Our results clearly show that different external factors can promote protein aggregation following different pathways. PeerJ Inc. 2020-06-12 /pmc/articles/PMC7295030/ /pubmed/32566392 http://dx.doi.org/10.7717/peerj.9178 Text en ©2020 Fernández-Silva et al. https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Biochemistry
Fernández-Silva, Arline
French-Pacheco, Leidys
Rivillas-Acevedo, Lina
Amero, Carlos
Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods
title Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods
title_full Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods
title_fullStr Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods
title_full_unstemmed Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods
title_short Aggregation pathways of human γ D crystallin induced by metal ions revealed by time dependent methods
title_sort aggregation pathways of human γ d crystallin induced by metal ions revealed by time dependent methods
topic Biochemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7295030/
https://www.ncbi.nlm.nih.gov/pubmed/32566392
http://dx.doi.org/10.7717/peerj.9178
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