BUTANEDIONE MONOXIME SUPPRESSES CONTRACTION AND ATPASE ACTIVITY OF RABBIT SKELETAL-MUSCLE
BUTANEDIONE MONOXIME SUPPRESSES CONTRACTION AND ATPASE ACTIVITY OF RABBIT SKELETAL-MUSCLE
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DOI：
10.1093/oxfordjournals.jbchem.a122717
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发表时间：
1989-04-01
影响因子：
2.7
通讯作者：
TAKEMORI, S
中科院分区：
文献类型：
--
作者：
HIGUCHI, H;TAKEMORI, S
以兔骨骼肌为实验材料，研究了2，3-丁二酮-2-单肟(BDM)对甘油纤维的力学反应及重肌球蛋白(HMM)和肌原纤维ATPase活性的影响。在相同条件下(离子强度0.06~0.2M，0.4~4 mM镁ATP，0~20 mM BDM，2~20度)测定力学响应和ATPase活性。C和pH 7.0)。BDM可逆地降低了纤维的等长张力、缩短速度和瞬时硬度。BDM还抑制肌原纤维和HMM-ATPase活性。肌动蛋白或肌钙蛋白-原肌球蛋白-肌动蛋白对HMM-ATPase活性的抑制作用不受影响。高温和低离子强度减弱了BDM对肌纤维收缩和收缩肌原纤维的ATPase活性的抑制，但对肌球蛋白HMM、Acto-HMM和松弛的肌原纤维ATPase活性无明显影响.起始磷酸盐的大小在20℃爆裂.C与BDM的浓度无关.这些结果表明，BDM对肌纤维收缩的抑制主要是由于BDM对肌球蛋白分子的直接作用.
The effects of 2,3-butanedione 2-monoxime (BDM) on mechanical responses of glycerinated fibers and the ATPase activity of heavy meromyosin (HMM) and myofibrils have been studied using rabbit skeletal muscle. The mechanical responses and the ATPase activity were measured in similar conditions (ionic strength 0.06-0.2 M, 0.4-4 mM MgATP, 0-20 mM BDM, 2-20.degree. C and pH 7.0). BDM reversibly reduced the isometric tension, shortening speed, and instantaneous stiffness of the fibers. BDM also inhibited myofibrillar and HMM ATPase activities. The inhibitory effect on the relative ATPase activity of HMM was not influenced by the addition of actin or troponin-tropomyosin-actin. High temperature and low ionic strength weakened BDM''s suppression of contraction of the fibers and the ATPase activity of contracting myofibrils, but not of the HMM, acto-HMM and relaxed myofibrillar ATPase activity. The size of the initial phosphate burst at 20.degree. C was independent of the concentration of BDM. These results suggest that the suppression of contraction of muscle fibers is due mainly to direct action of BDM on the myosin molecules.