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

FEBS Letters

Liu, Qi-Yi¹  Shen, Win K.¹  Strauss, Harold C.¹  Lai, F.Anthony²  Meissner, Gerhard² 

[1] Departments of Medicine and Pharmacology, Duke University Medical Center, Durham, NC, USA;The Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, USA

关键词: Potassium channel;    Sarcoplasmic reticulum;    Protein purification;    Lipid bilayer;    Cardiac muscle;    Chaps;    Chaps;    3-[(3cholamidopropyl)dimethylammonio]-1-propanesulfonate;   

DOI  :  10.1016/0014-5793(91)81092-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 M _r ∼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.

【 授权许可】

Unknown