Similar Ca2+ dependences of [3H]ryanodine binding to alpha- and beta-ryanodine receptors purified from bullfrog skeletal muscle in an isotonic medium.
To understand the functions of the two ryanodine receptor isoforms (alpha- and beta-RyRs) in nonmammalian skeletal muscles, we determined [3H]ryanodine binding to these isoforms purified from bullfrog skeletal muscle. In 0.17 M-NaCl medium both isoforms demonstrated similar Ca2+ dependent ryanodine binding activities, while the Ca2+ sensitivity for activation of beta-RyR was increased in 1 M-NaCl medium. This enhancement in Ca2+ sensitivity depended on the kinds of salts used. These results imply that alpha- and beta-RyRs may have similar properties as Ca2+-induced Ca2+ release channels in bullfrog skeletal muscle.
Murayama
T
T
Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan.
Ogawa
Y
Y
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D002793:Cholic Acids / Q000494:pharmacology; D009124:Muscle Proteins / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry*; D010743:Phospholipids / Q000494:pharmacology; D011892:Rana catesbeiana; D012433:Ryanodine / Q000378:metabolism*; D019837:Ryanodine Receptor Calcium Release Channel; D012965:Sodium Chloride; D014316:Tritium
D015220:Calcium Channels; D002793:Cholic Acids; D009124:Muscle Proteins; D010743:Phospholipids; D019837:Ryanodine Receptor Calcium Release Channel; D014316:Tritium; D012433:Ryanodine; C005147:5'-adenylyl (beta,gamma-methylene)diphosphonate; D002110:Caffeine; D012965:Sodium Chloride; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate; D002118:Calcium