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Protein GB1 Folding and Assembly from Structural Elements.

Bauer, Mikael LU ; Xue, Wei-Feng LU and Linse, Sara LU (2009) In International Journal of Molecular Sciences 10(4). p.1552-1566
Abstract
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 beta-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... (More)
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 beta-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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Molecular Sciences
volume
10
issue
4
pages
1552 - 1566
publisher
MOLECULAR DIVERSITY PRESERVATION INT
external identifiers
  • wos:000265530600010
  • pmid:19468325
  • scopus:67149144180
ISSN
1422-0067
DOI
10.3390/ijms10041552
language
English
LU publication?
yes
id
f3771bb7-0c80-4d6e-bf16-26b17932496a (old id 1412015)
date added to LUP
2009-06-11 09:02:51
date last changed
2017-01-01 06:28:27
@article{f3771bb7-0c80-4d6e-bf16-26b17932496a,
  abstract     = {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 beta-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.},
  author       = {Bauer, Mikael and Xue, Wei-Feng and Linse, Sara},
  issn         = {1422-0067},
  language     = {eng},
  number       = {4},
  pages        = {1552--1566},
  publisher    = {MOLECULAR DIVERSITY PRESERVATION INT},
  series       = {International Journal of Molecular Sciences},
  title        = {Protein GB1 Folding and Assembly from Structural Elements.},
  url          = {http://dx.doi.org/10.3390/ijms10041552},
  volume       = {10},
  year         = {2009},
}