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Small heat shock proteins prevent aggregation of citrate synthase and bind to the N-terminal region which is absent in thermostable forms of citrate synthase

Åhrman, Emma LU ; Gustavsson, Niklas LU ; Hultschig, Claus; Boelens, Wilbert C. and Emanuelsson, Cecilia LU (2007) In Extremophiles 11(5). p.659-666
Abstract
Citrate synthase (CS) is often used in chaperone assays since this thermosensitive enzyme aggregates at moderately increased temperatures. Small heat shock proteins (sHsps) are molecular chaperones specialized in preventing the aggregation of other proteins, termed substrate proteins, under conditions of transient heat stress. To investigate the mechanism whereby sHsps bind to and stabilize a substrate protein, we here used peptide array screening covering the sequence of porcine CS (P00889). Strong binding of sHsps was detected to a peptide corresponding to the most N-terminal alpha-helix in CS (amino acids Leu(13) to Gln(27)). The N-terminal alpha-helices in the CS dimer intertwine with the C-terminus in the other subunit and together... (More)
Citrate synthase (CS) is often used in chaperone assays since this thermosensitive enzyme aggregates at moderately increased temperatures. Small heat shock proteins (sHsps) are molecular chaperones specialized in preventing the aggregation of other proteins, termed substrate proteins, under conditions of transient heat stress. To investigate the mechanism whereby sHsps bind to and stabilize a substrate protein, we here used peptide array screening covering the sequence of porcine CS (P00889). Strong binding of sHsps was detected to a peptide corresponding to the most N-terminal alpha-helix in CS (amino acids Leu(13) to Gln(27)). The N-terminal alpha-helices in the CS dimer intertwine with the C-terminus in the other subunit and together form a stem-like structure which is protruding from the CS dimer. This stem-like structure is absent in thermostable forms of CS from thermophilic archaebacteria like Pyrococcus furiosus and Sulfolobus solfatacarium. These data therefore suggest that thermostabilization of thermosensitive CS by sHsps is achieved by stabilization of the C- and N-terminae in the protruding thermosensitive softspot, which is absent in thermostable forms of the CS dimer. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
stability, protein, protein-protein interactions, heat stress, chaperones, thermosensitivity
in
Extremophiles
volume
11
issue
5
pages
659 - 666
publisher
Springer
external identifiers
  • wos:000249119300002
  • scopus:34548309201
ISSN
1433-4909
DOI
10.1007/s00792-007-0080-3
language
English
LU publication?
yes
id
13f62cb1-3b92-4a47-82ac-3046f49810c9 (old id 688052)
date added to LUP
2007-12-11 13:18:37
date last changed
2017-07-02 03:28:25
@article{13f62cb1-3b92-4a47-82ac-3046f49810c9,
  abstract     = {Citrate synthase (CS) is often used in chaperone assays since this thermosensitive enzyme aggregates at moderately increased temperatures. Small heat shock proteins (sHsps) are molecular chaperones specialized in preventing the aggregation of other proteins, termed substrate proteins, under conditions of transient heat stress. To investigate the mechanism whereby sHsps bind to and stabilize a substrate protein, we here used peptide array screening covering the sequence of porcine CS (P00889). Strong binding of sHsps was detected to a peptide corresponding to the most N-terminal alpha-helix in CS (amino acids Leu(13) to Gln(27)). The N-terminal alpha-helices in the CS dimer intertwine with the C-terminus in the other subunit and together form a stem-like structure which is protruding from the CS dimer. This stem-like structure is absent in thermostable forms of CS from thermophilic archaebacteria like Pyrococcus furiosus and Sulfolobus solfatacarium. These data therefore suggest that thermostabilization of thermosensitive CS by sHsps is achieved by stabilization of the C- and N-terminae in the protruding thermosensitive softspot, which is absent in thermostable forms of the CS dimer.},
  author       = {Åhrman, Emma and Gustavsson, Niklas and Hultschig, Claus and Boelens, Wilbert C. and Emanuelsson, Cecilia},
  issn         = {1433-4909},
  keyword      = {stability,protein,protein-protein interactions,heat stress,chaperones,thermosensitivity},
  language     = {eng},
  number       = {5},
  pages        = {659--666},
  publisher    = {Springer},
  series       = {Extremophiles},
  title        = {Small heat shock proteins prevent aggregation of citrate synthase and bind to the N-terminal region which is absent in thermostable forms of citrate synthase},
  url          = {http://dx.doi.org/10.1007/s00792-007-0080-3},
  volume       = {11},
  year         = {2007},
}