A new scorpion polypeptide enhances the binding of radiolabeled-ryanodine on ryanodine receptor in sarcoplasmic reticulum of rabbit skeletal muscle

1997 ◽  
Vol 42 (2) ◽  
pp. 147-151 ◽  
Author(s):  
Yonghua Ji ◽  
Ke Xu ◽  
Seiko Kawano ◽  
Yoshiyuki Hirayama ◽  
Masayasu Hiraoka ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Ryanodine Receptor ◽  
Rabbit Skeletal Muscle

scholarly journals Purified ryanodine receptor from rabbit skeletal muscle is the calcium-release channel of sarcoplasmic reticulum.

1988 ◽  
Vol 92 (1) ◽  
pp. 1-26 ◽  
Author(s):  
J S Smith ◽  
T Imagawa ◽  
J Ma ◽  
M Fill ◽  
K P Campbell ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Ryanodine Receptor ◽  
Calcium Release ◽  
Binding Capacity ◽  
Ruthenium Red ◽  
Rabbit Skeletal Muscle ◽  
Permeability Ratio ◽  
Calcium Release Channel ◽  
Release Channel

The ryanodine receptor of rabbit skeletal muscle sarcoplasmic reticulum was purified as a single 450,000-dalton polypeptide from CHAPS-solubilized triads using immunoaffinity chromatography. The purified receptor had a [3H]ryanodine-binding capacity (Bmax) of 490 pmol/mg and a binding affinity (Kd) of 7.0 nM. Using planar bilayer recording techniques, we show that the purified receptor forms cationic channels selective for divalent ions. Ryanodine receptor channels were identical to the Ca-release channels described in native sarcoplasmic reticulum using the same techniques. In the present work, four criteria were used to establish this identity: (a) activation of channels by micromolar Ca and millimolar ATP and inhibition by micromolar ruthenium red, (b) a main channel conductance of 110 +/- 10 pS in 54 mM trans Ca, (c) a long-term open state of lower unitary conductance induced by ryanodine concentrations as low as 20 nM, and (d) a permeability ratio PCa/PTris approximately equal to 14. In addition, we show that the purified ryanodine receptor channel displays a saturable conductance in both monovalent and divalent cation solutions (gamma max for K and Ca = 1 nS and 172 pS, respectively). In the absence of Ca, channels had a broad selectivity for monovalent cations, but in the presence of Ca, they were selectively permeable to Ca against K by a permeability ratio PCa/PK approximately equal to 6. Receptor channels displayed several equivalent conductance levels, which suggest an oligomeric pore structure. We conclude that the 450,000-dalton polypeptide ryanodine receptor is the Ca-release channel of the sarcoplasmic reticulum and is the target site of ruthenium red and ryanodine.

scholarly journals Transmembrane orientation of the N-terminal and C-terminal ends of the ryanodine receptor in the sarcoplasmic reticulum of rabbit skeletal muscle

1994 ◽  
Vol 298 (3) ◽  
pp. 743-749 ◽  
Author(s):  
I Marty ◽  
M Villaz ◽  
G Arlaud ◽  
I Bally ◽  
M Ronjat
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Ryanodine Receptor ◽  
Synthetic Peptides ◽  
Rabbit Skeletal Muscle ◽  
Cytoplasmic Localization ◽  
Carboxypeptidase A ◽  
Western Blots ◽  
C Terminus ◽  
Cytoplasmic Side

Antibodies were raised against synthetic peptides corresponding to the N-terminal (residues 2-15) and the C-terminal (residues 5027-5037) parts of the rabbit skeletal muscle ryanodine receptor. The specificity of the antibodies generated was tested by e.l.i.s.a., Western blotting and immunofluorescence. All these tests demonstrated the specificity of the antibodies and their ability to react with both the native and the denaturated ryanodine receptor. Both the anti-N-terminus and the anti-C-terminus antibodies bound to sarcoplasmic reticulum vesicles, indicating that each end of the membrane-embedded ryanodine receptor is exposed to the cytoplasmic side of the vesicles. These immunological data were complemented with proteolysis experiments using carboxypeptidase A. Carboxypeptidase A induced degradation of the C-terminal end of the ryanodine receptor in sarcoplasmic reticulum vesicles and a concomitant loss of reactivity of the anti-C-terminus antibodies in Western blots, providing extra evidence for the cytoplasmic localization of the C-terminal end of the ryanodine receptor.

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