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Interplay of buried histidine protonation and protein stability in prion misfolding
Misofolding of mammalian prion proteins (PrP) is believed to be the cause of a group of rare and fatal neurodegenerative diseases. Despite intense scrutiny however, the mechanism of the misfolding reaction remains unclear. We perform nuclear Magnetic Resonance and thermodynamic stability measurement...
Autores principales: | , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429843/ https://www.ncbi.nlm.nih.gov/pubmed/28408762 http://dx.doi.org/10.1038/s41598-017-00954-7 |
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author | Malevanets, Anatoly Chong, P. Andrew Hansen, D. Flemming Rizk, Paul Sun, Yulong Lin, Hong Muhandiram, Ranjith Chakrabartty, Avi Kay, Lewis E. Forman-Kay, Julie D. Wodak, Shoshana J. |
author_facet | Malevanets, Anatoly Chong, P. Andrew Hansen, D. Flemming Rizk, Paul Sun, Yulong Lin, Hong Muhandiram, Ranjith Chakrabartty, Avi Kay, Lewis E. Forman-Kay, Julie D. Wodak, Shoshana J. |
author_sort | Malevanets, Anatoly |
collection | PubMed |
description | Misofolding of mammalian prion proteins (PrP) is believed to be the cause of a group of rare and fatal neurodegenerative diseases. Despite intense scrutiny however, the mechanism of the misfolding reaction remains unclear. We perform nuclear Magnetic Resonance and thermodynamic stability measurements on the C-terminal domains (residues 90–231) of two PrP variants exhibiting different pH-induced susceptibilities to aggregation: the susceptible hamster prion (GHaPrP) and its less susceptible rabbit homolog (RaPrP). The pKa of histidines in these domains are determined from titration experiments, and proton-exchange rates are measured at pH 5 and pH 7. A single buried highly conserved histidine, H187/H186 in GHaPrP/RaPrP, exhibited a markedly down shifted pKa ~5 for both proteins. However, noticeably larger pH-induced shifts in exchange rates occur for GHaPrP versus RaPrP. Analysis of the data indicates that protonation of the buried histidine destabilizes both PrP variants, but produces a more drastic effect in the less stable GHaPrP. This interpretation is supported by urea denaturation experiments performed on both PrP variants at neutral and low pH, and correlates with the difference in disease susceptibility of the two species, as expected from the documented linkage between destabilization of the folded state and formation of misfolded and aggregated species. |
format | Online Article Text |
id | pubmed-5429843 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-54298432017-05-15 Interplay of buried histidine protonation and protein stability in prion misfolding Malevanets, Anatoly Chong, P. Andrew Hansen, D. Flemming Rizk, Paul Sun, Yulong Lin, Hong Muhandiram, Ranjith Chakrabartty, Avi Kay, Lewis E. Forman-Kay, Julie D. Wodak, Shoshana J. Sci Rep Article Misofolding of mammalian prion proteins (PrP) is believed to be the cause of a group of rare and fatal neurodegenerative diseases. Despite intense scrutiny however, the mechanism of the misfolding reaction remains unclear. We perform nuclear Magnetic Resonance and thermodynamic stability measurements on the C-terminal domains (residues 90–231) of two PrP variants exhibiting different pH-induced susceptibilities to aggregation: the susceptible hamster prion (GHaPrP) and its less susceptible rabbit homolog (RaPrP). The pKa of histidines in these domains are determined from titration experiments, and proton-exchange rates are measured at pH 5 and pH 7. A single buried highly conserved histidine, H187/H186 in GHaPrP/RaPrP, exhibited a markedly down shifted pKa ~5 for both proteins. However, noticeably larger pH-induced shifts in exchange rates occur for GHaPrP versus RaPrP. Analysis of the data indicates that protonation of the buried histidine destabilizes both PrP variants, but produces a more drastic effect in the less stable GHaPrP. This interpretation is supported by urea denaturation experiments performed on both PrP variants at neutral and low pH, and correlates with the difference in disease susceptibility of the two species, as expected from the documented linkage between destabilization of the folded state and formation of misfolded and aggregated species. Nature Publishing Group UK 2017-04-13 /pmc/articles/PMC5429843/ /pubmed/28408762 http://dx.doi.org/10.1038/s41598-017-00954-7 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Malevanets, Anatoly Chong, P. Andrew Hansen, D. Flemming Rizk, Paul Sun, Yulong Lin, Hong Muhandiram, Ranjith Chakrabartty, Avi Kay, Lewis E. Forman-Kay, Julie D. Wodak, Shoshana J. Interplay of buried histidine protonation and protein stability in prion misfolding |
title | Interplay of buried histidine protonation and protein stability in prion misfolding |
title_full | Interplay of buried histidine protonation and protein stability in prion misfolding |
title_fullStr | Interplay of buried histidine protonation and protein stability in prion misfolding |
title_full_unstemmed | Interplay of buried histidine protonation and protein stability in prion misfolding |
title_short | Interplay of buried histidine protonation and protein stability in prion misfolding |
title_sort | interplay of buried histidine protonation and protein stability in prion misfolding |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429843/ https://www.ncbi.nlm.nih.gov/pubmed/28408762 http://dx.doi.org/10.1038/s41598-017-00954-7 |
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