Advanced

The effects of caldesmon extraction on mechanical properties of skinned smooth muscle fibre preparations

Malmqvist, Ulf LU ; Arner, A; Makuch, R and Dabrowska, R (1996) In Pflügers Archiv 432(2). p.241-247
Abstract
The role of caldesmon in the regulation of smooth muscle contraction was investigated in chemically skinned smooth muscle fibres from the guinea-pig taenia coli. A 19-kDa C-terminal fragment of caldesmon gave a minor (<5%) reduction of force in fully thiophosphorylated fibres, but reduced force by about 50% at intermediate activation levels without affecting the level of light chain phosphorylation. An extraction procedure was developed using incubation in solutions containing high Mg2+ concentrations. Protein analysis revealed a selective decrease in the amount of caldesmon in the fibres. Maximal active force per cross-sectional area was unaffected. The Ca2+ dependence of active force was shifted towards lower Ca2+ concentrations and... (More)
The role of caldesmon in the regulation of smooth muscle contraction was investigated in chemically skinned smooth muscle fibres from the guinea-pig taenia coli. A 19-kDa C-terminal fragment of caldesmon gave a minor (<5%) reduction of force in fully thiophosphorylated fibres, but reduced force by about 50% at intermediate activation levels without affecting the level of light chain phosphorylation. An extraction procedure was developed using incubation in solutions containing high Mg2+ concentrations. Protein analysis revealed a selective decrease in the amount of caldesmon in the fibres. Maximal active force per cross-sectional area was unaffected. The Ca2+ dependence of active force was shifted towards lower Ca2+ concentrations and became less steep. The effects of extraction of caldesmon could in part be reversed by incubation in a solution containing purified caldesmon. The results are consistent with the hypothesis that caldesmon in smooth muscle thin filaments inhibits force generation and plays a role in regulating cooperative attachment of cross-bridges at sub-maximal levels of activation in smooth muscle. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Skinned smooth muscle, Caldesmon, 19-kDa fragment, Calcium sensitivity
in
Pflügers Archiv
volume
432
issue
2
pages
241 - 247
publisher
Springer
external identifiers
  • pmid:8662300
  • scopus:0029957346
ISSN
0031-6768
DOI
10.1007/s004240050130
language
English
LU publication?
yes
id
18d2527a-6aac-4742-aa7e-7b8cf9bc8a97 (old id 1110909)
date added to LUP
2008-07-25 16:53:54
date last changed
2017-01-01 07:22:13
@article{18d2527a-6aac-4742-aa7e-7b8cf9bc8a97,
  abstract     = {The role of caldesmon in the regulation of smooth muscle contraction was investigated in chemically skinned smooth muscle fibres from the guinea-pig taenia coli. A 19-kDa C-terminal fragment of caldesmon gave a minor (&lt;5%) reduction of force in fully thiophosphorylated fibres, but reduced force by about 50% at intermediate activation levels without affecting the level of light chain phosphorylation. An extraction procedure was developed using incubation in solutions containing high Mg2+ concentrations. Protein analysis revealed a selective decrease in the amount of caldesmon in the fibres. Maximal active force per cross-sectional area was unaffected. The Ca2+ dependence of active force was shifted towards lower Ca2+ concentrations and became less steep. The effects of extraction of caldesmon could in part be reversed by incubation in a solution containing purified caldesmon. The results are consistent with the hypothesis that caldesmon in smooth muscle thin filaments inhibits force generation and plays a role in regulating cooperative attachment of cross-bridges at sub-maximal levels of activation in smooth muscle.},
  author       = {Malmqvist, Ulf and Arner, A and Makuch, R and Dabrowska, R},
  issn         = {0031-6768},
  keyword      = {Skinned smooth muscle,Caldesmon,19-kDa fragment,Calcium sensitivity},
  language     = {eng},
  number       = {2},
  pages        = {241--247},
  publisher    = {Springer},
  series       = {Pflügers Archiv},
  title        = {The effects of caldesmon extraction on mechanical properties of skinned smooth muscle fibre preparations},
  url          = {http://dx.doi.org/10.1007/s004240050130},
  volume       = {432},
  year         = {1996},
}