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Protein GB1 Folding and Assembly from Structural Elements

Folding of the Protein G B1 domain (PGB1) shifts with increasing salt concentration from a cooperative assembly of inherently unstructured subdomains to an assembly of partly pre-folded structures. The salt-dependence of pre-folding contributes to the stability minimum observed at physiological salt...

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Autores principales: Bauer, Mikael C., Xue, Wei-Feng, Linse, Sara
Formato: Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International (MDPI) 2009
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680633/
https://www.ncbi.nlm.nih.gov/pubmed/19468325
http://dx.doi.org/10.3390/ijms10041552
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author Bauer, Mikael C.
Xue, Wei-Feng
Linse, Sara
author_facet Bauer, Mikael C.
Xue, Wei-Feng
Linse, Sara
author_sort Bauer, Mikael C.
collection PubMed
description Folding of the Protein G B1 domain (PGB1) shifts with increasing salt concentration from a cooperative assembly of inherently unstructured subdomains to an assembly of partly pre-folded structures. The salt-dependence of pre-folding contributes to the stability minimum observed at physiological salt conditions. Our conclusions are based on a study in which the reconstitution of PGB1 from two fragments was studied as a function of salt concentrations and temperature using circular dichroism spectroscopy. Salt was found to induce an increase in β-hairpin structure for the C-terminal fragment (residues 41 – 56), whereas no major salt effect on structure was observed for the isolated N-terminal fragment (residues 1 – 41). In line with the increasing evidence on the interrelation between fragment complementation and stability of the corresponding intact protein, we also find that salt effects on reconstitution can be predicted from salt dependence of the stability of the intact protein. Our data show that our variant (which has the mutations T2Q, N8D, N37D and reconstitutes in a manner similar to the wild type) displays the lowest equilibrium association constant around physiological salt concentration, with higher affinity observed both at lower and higher salt concentration. This corroborates the salt effects on the stability towards denaturation of the intact protein, for which the stability at physiological salt is lower compared to both lower and higher salt concentrations. Hence we conclude that reconstitution reports on molecular factors that govern the native states of proteins.
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spelling pubmed-26806332009-05-22 Protein GB1 Folding and Assembly from Structural Elements Bauer, Mikael C. Xue, Wei-Feng Linse, Sara Int J Mol Sci Article Folding of the Protein G B1 domain (PGB1) shifts with increasing salt concentration from a cooperative assembly of inherently unstructured subdomains to an assembly of partly pre-folded structures. The salt-dependence of pre-folding contributes to the stability minimum observed at physiological salt conditions. Our conclusions are based on a study in which the reconstitution of PGB1 from two fragments was studied as a function of salt concentrations and temperature using circular dichroism spectroscopy. Salt was found to induce an increase in β-hairpin structure for the C-terminal fragment (residues 41 – 56), whereas no major salt effect on structure was observed for the isolated N-terminal fragment (residues 1 – 41). In line with the increasing evidence on the interrelation between fragment complementation and stability of the corresponding intact protein, we also find that salt effects on reconstitution can be predicted from salt dependence of the stability of the intact protein. Our data show that our variant (which has the mutations T2Q, N8D, N37D and reconstitutes in a manner similar to the wild type) displays the lowest equilibrium association constant around physiological salt concentration, with higher affinity observed both at lower and higher salt concentration. This corroborates the salt effects on the stability towards denaturation of the intact protein, for which the stability at physiological salt is lower compared to both lower and higher salt concentrations. Hence we conclude that reconstitution reports on molecular factors that govern the native states of proteins. Molecular Diversity Preservation International (MDPI) 2009-04-08 /pmc/articles/PMC2680633/ /pubmed/19468325 http://dx.doi.org/10.3390/ijms10041552 Text en © 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0 This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Bauer, Mikael C.
Xue, Wei-Feng
Linse, Sara
Protein GB1 Folding and Assembly from Structural Elements
title Protein GB1 Folding and Assembly from Structural Elements
title_full Protein GB1 Folding and Assembly from Structural Elements
title_fullStr Protein GB1 Folding and Assembly from Structural Elements
title_full_unstemmed Protein GB1 Folding and Assembly from Structural Elements
title_short Protein GB1 Folding and Assembly from Structural Elements
title_sort protein gb1 folding and assembly from structural elements
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680633/
https://www.ncbi.nlm.nih.gov/pubmed/19468325
http://dx.doi.org/10.3390/ijms10041552
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