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 language | English (US) |
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Pages (from-to) | 13-16 |
Number of pages | 4 |
Journal | FEBS Letters |
Volume | 291 |
Issue number | 1 |
DOIs | |
State | Published - 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