Mikhaĭlova M V, Safarian E Kh, Nesterov V P
Zh Evol Biokhim Fiziol. 1987 Mar-Apr;23(2):180-5.
Using differential centrifugation in sucrose density gradient, from muscles of the frog fractions were obtained which contain fragments of sarcolemma, as well as membranes of T-system tubules and sarcoplasmic reticulum. In isolated membrane fractions, studies were made on the activity of cation-stimulated ATPases (Na+, K+-, Ca2+, Mg2+- and Mg2+-ATPases). Enzymic and electrophoretic analyses showed that the highest content of Mg2+-ATPases is typical of the fractions which are located on the surface of 35% sucrose. The data obtained indicate that Mg2+-ATPase is the enzyme which is specific for the membranes of T-system tubules in skeletal muscles of not only birds but amphibians as well. From cardiac muscle of the frog, membrane fraction was isolated which is similar (with respect to its predominant content of Mg2+-ATPase) to the membranes of T-system tubules. It is suggested that the presence of Mg2+-ATPase in these membranes is a common property of phasic striated muscle fibers in all mature vertebrate animals.
利用蔗糖密度梯度差速离心法，从青蛙肌肉中获得了含有肌膜片段以及T系统小管和肌浆网的膜的组分。对分离出的膜组分进行了阳离子刺激的ATP酶（Na⁺、K⁺ -、Ca²⁺、Mg²⁺ -和Mg²⁺ -ATP酶）活性的研究。酶学和电泳分析表明，Mg²⁺ -ATP酶含量最高是位于35%蔗糖表面的组分的典型特征。所获得的数据表明，Mg²⁺ -ATP酶不仅是鸟类骨骼肌，也是两栖动物骨骼肌中T系统小管膜特有的酶。从青蛙的心肌中分离出了膜组分，该组分（就其Mg²⁺ -ATP酶的主要含量而言）与T系统小管的膜相似。有人提出，这些膜中存在Mg²⁺ -ATP酶是所有成熟脊椎动物的相性横纹肌纤维的共同特性。
