Reconstitution of the solubilized cardiac sarcoplasmic reticulum potassium channel Identification of a putative Mr ∼80 kDa polypeptide constituent

Qi Yi Liu, F. Anthony Lai, Win K. Shen, Gerhard Meissner, Harold C. Strauss

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

Recent evidence has indicated that potassium ion movement through sarcoplasmic reticulum (SR) K+ channels is an important countercurrent for Ca2+ release from SR. We used Chaps-solubilized SR vesicles and sucrose density gradient centrifugation to identify components of the canine cardiac SR K+ channel. To overcome the difficulty of the absence of a high-affinity specific ligand, we have successfully applied the planar lipid bilayer reconstitution technique to identify and functionally assay for the solubilized SR K+ channel. We found that Chaps solubilization of the channel did not change the protein's functional properties. The cardiac SR K+ channel sediments as a 15-20S protein complex. A polypeptide of Mr ∼80 kDa was found to specifically comigrate with the 15-20S gradient fractions and might be a major constituent of the cardiac SR K+ channel.

Original languageEnglish (US)
Pages (from-to)13-16
Number of pages4
JournalFEBS Letters
Volume291
Issue number1
DOIs
StatePublished - Oct 7 1991

Keywords

  • Cardiac muscle
  • Chaps
  • Lipid bilayer
  • Potassium channel
  • Protein purification
  • Sarcoplasmic reticulum

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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