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The chaperone-like activity of a small heat shock protein is lost after sulfoxidation of conserved methionines in a surface-exposed amphipathic α-helix

Härndahl, Ulrika; Kokke, Bas P.A.; Gustavsson, Niklas LU ; Linse, Sara LU ; Berggren, Kristina; Tjerneld, Folke LU ; Boelens, Wilbert C. and Sundby, Cecilia (2001) In BBA - Protein Structure and Molecular Enzymology1982-01-01+01:002002-01-01+01:00 1545(1-2). p.227-237
Abstract
The small heat shock proteins (sHsps) possess a chaperone-like activity which prevents aggregation of other proteins during transient heat or oxidative stress. The sHsps bind, onto their surface, molten globule forms of other proteins, thereby keeping them in a refolding competent state. In Hsp21, a chloroplast-located sHsp in all higher plants, there is a highly conserved region forming an amphipathic α-helix with several methionines on the hydrophobic side according to secondary structure prediction. This paper describes how sulfoxidation of the methionines in this amphipathic α-helix caused conformational changes and a reduction in the Hsp21 oligomer size, and a complete loss of the chaperone-like activity. Concomitantly, there was a... (More)
The small heat shock proteins (sHsps) possess a chaperone-like activity which prevents aggregation of other proteins during transient heat or oxidative stress. The sHsps bind, onto their surface, molten globule forms of other proteins, thereby keeping them in a refolding competent state. In Hsp21, a chloroplast-located sHsp in all higher plants, there is a highly conserved region forming an amphipathic α-helix with several methionines on the hydrophobic side according to secondary structure prediction. This paper describes how sulfoxidation of the methionines in this amphipathic α-helix caused conformational changes and a reduction in the Hsp21 oligomer size, and a complete loss of the chaperone-like activity. Concomitantly, there was a loss of an outer-surface located α-helix as determined by limited proteolysis and circular dichroism spectroscopy. The present data indicate that the methionine-rich amphipathic α-helix, a motif of unknown physiological significance which evolved during the land plant evolution, is crucial for binding of substrate proteins and has rendered the chaperone-like activity of Hsp21 very dependent on the chloroplast redox state. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Small heat shock protein, Methionine sulfoxidation, Chaperone, Oligomer, Amphipathic α-helix
in
BBA - Protein Structure and Molecular Enzymology1982-01-01+01:002002-01-01+01:00
volume
1545
issue
1-2
pages
227 - 237
publisher
Elsevier
external identifiers
  • scopus:0035830637
ISSN
0167-4838
DOI
language
English
LU publication?
yes
id
3627fcb8-4d59-47a9-b3f8-c00a9c502479 (old id 125008)
date added to LUP
2007-07-05 15:08:13
date last changed
2018-05-29 09:44:02
@article{3627fcb8-4d59-47a9-b3f8-c00a9c502479,
  abstract     = {The small heat shock proteins (sHsps) possess a chaperone-like activity which prevents aggregation of other proteins during transient heat or oxidative stress. The sHsps bind, onto their surface, molten globule forms of other proteins, thereby keeping them in a refolding competent state. In Hsp21, a chloroplast-located sHsp in all higher plants, there is a highly conserved region forming an amphipathic α-helix with several methionines on the hydrophobic side according to secondary structure prediction. This paper describes how sulfoxidation of the methionines in this amphipathic α-helix caused conformational changes and a reduction in the Hsp21 oligomer size, and a complete loss of the chaperone-like activity. Concomitantly, there was a loss of an outer-surface located α-helix as determined by limited proteolysis and circular dichroism spectroscopy. The present data indicate that the methionine-rich amphipathic α-helix, a motif of unknown physiological significance which evolved during the land plant evolution, is crucial for binding of substrate proteins and has rendered the chaperone-like activity of Hsp21 very dependent on the chloroplast redox state.},
  author       = {Härndahl, Ulrika and Kokke, Bas P.A. and Gustavsson, Niklas and Linse, Sara and Berggren, Kristina and Tjerneld, Folke and Boelens, Wilbert C. and Sundby, Cecilia},
  issn         = {0167-4838},
  keyword      = {Small heat shock protein,Methionine sulfoxidation,Chaperone,Oligomer,Amphipathic α-helix},
  language     = {eng},
  number       = {1-2},
  pages        = {227--237},
  publisher    = {Elsevier},
  series       = {BBA - Protein Structure and Molecular Enzymology1982-01-01+01:002002-01-01+01:00},
  title        = {The chaperone-like activity of a small heat shock protein is lost after sulfoxidation of conserved methionines in a surface-exposed amphipathic α-helix},
  url          = {http://dx.doi.org/},
  volume       = {1545},
  year         = {2001},
}