SOLUBILIZATION OF THE NITRENDIPINE RECEPTOR FROM SKELETAL-MUSCLE TRANSVERSE TUBULE MEMBRANES - INTERACTIONS WITH SPECIFIC INHIBITORS OF THE VOLTAGE-DEPENDENT CA-2+ CHANNEL
SOLUBILIZATION OF THE NITRENDIPINE RECEPTOR FROM SKELETAL-MUSCLE TRANSVERSE TUBULE MEMBRANES - INTERACTIONS WITH SPECIFIC INHIBITORS OF THE VOLTAGE-DEPENDENT CA-2+ CHANNEL
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DOI：
10.1111/j.1432-1033.1984.tb08307.x
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发表时间：
1984-01-01
期刊：
影响因子：
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通讯作者：
LAZDUNSKI, M
中科院分区：
文献类型：
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作者：
BORSOTTO, M;NORMAN, RI;LAZDUNSKI, M
兔骨骼肌横小管膜电压依赖性钙通道的尼群地平受体被去污剂溶解。使用3-[（3-胆酰胺丙基）二甲基-铵基]-1-丙磺酸盐作为去污剂，磷脂或甘油作为稳定剂，获得高度稳定的增溶受体制剂。[~ 3 H]尼群地平与增溶受体的结合是可逆的和饱和的。在4.5度。[~ 3 H]尼群地平受体复合物的平衡解离常数为7.0 ± 1.0。3 nM，并且接近于由结合速率常数（k1 = 1.3 × 105 M-1 s-1）和解离速率常数（k-1 = 1.10 × 105 M-1 s-1）测定的结果。10-3 s-1）的8.4 nM。尼群地平的浓度，给半最大抑制[3 H]尼群地平结合到溶解的受体是10 nM，这是类似的解离常数测定的放射性标记的配体的值。[3 H]尼群地平与其可溶性受体的结合也被其他抗心律失常药物如苄普地尔和维拉帕米抑制，并被d-顺式地尔硫卓增强。由于这些药物是[3 H]尼群地平结合的明显的非竞争性抑制剂，因此得出结论，这些不同的结合位点是紧密偶联的。用蔗糖密度沉降法分离了3个[~ 3 H]尼群地平结合活性，表观沉降系数分别为11.4S、14.4S和21 S。
The nitrendipine receptor associated with the voltage-dependent Ca channel from rabbit skeletal muscle transverse tubule membranes has been solubilized by detergent extraction. A highly stable solubilized receptor preparation was obtained using 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate as detergent with phospholipids or glycerol present as stabilizing agents. Binding of [3H]nitrendipine to the solubilized receptor was reversible and saturable. At 4.degree. C the equilibrium dissociation constant of the [3H]nitrendipine receptor complex was 7 .+-. 3 nM and was close to that determined from the rate constants of association (k1 = 1.3 105 M-1 s-1) and dissociation (k-1 = 1.10 .times. 10-3 s-1) of 8.4 nM. The nitrendipine concentration that gave a half-maximal inhibition of [3H]nitrendipine binding to the solubilized receptor was 10 nM, which was similar to the values for the dissociation constant determined for the radiolabeled ligand. [3H]Nitrendipine binding to its solubilized receptor was also inhibited by other antiarrythmic drugs, such as bepridil and verapamil, and enhanced by d-cis-diltiazem. Since these drugs are apparent non-competitive inhibitors of [3H]nitrendipine binding it was concluded that these different binding sites are tightly coupled. Sucrose density sedimentation of solubilized nitrendipine receptor resulted in the separation of 3 [3H]nitrendipine binding activities with apparent sedimentation coefficients of 11.4S, 14.4S and 21S.