Interaction between Glycogen Phosphorylase and Sarcoplasmic Reticulum Membranes and Its Functional Implications (*)
Interaction between Glycogen Phosphorylase and Sarcoplasmic Reticulum Membranes and Its Functional Implications (*)
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糖原磷酸化酶与肌浆网膜之间的相互作用及其功能意义 (*)
DOI：
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发表时间：
1995
影响因子：
4.8
通讯作者：
C. Gutiérrez
中科院分区：
文献类型：
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作者：
A. Cuenda;M. Nogues;F. Henao;C. Gutiérrez
在25℃、生理pH和离子强度条件下，骨骼肌糖原磷酸化酶b结合到肌浆网(SR)膜上的解离常数为1.7±0.6 mg/ml。将温度提高到37℃时，解离常数降低2-3倍。SR膜可结合1.1±0.1 mg糖原磷酸化酶b/mg SR蛋白，而用内源性SR脂和重组Ca-ATPase制备的脂质体不能结合糖原磷酸化酶。在AMP存在的情况下，糖原磷酸化酶b与SR膜的结合伴随着其活性的抑制。与SR膜结合的糖原磷酸化酶b的Vmax是纯化的糖原磷酸化酶的40±5%，对其变构激活剂AMP和IMP的亲和力降低。当以淀粉或α-直链淀粉代替糖原作为底物时，纯化的糖原磷酸化酶b也观察到了这些动力学效应。用α-淀粉酶处理SR膜可使糖原磷酸化酶b从SR膜上解离。因此，结合到SR膜上的线性糖原多糖片段可能介导了糖原磷酸化酶b与这些膜的结合。
Skeletal muscle glycogen phosphorylase b binds to sarcoplasmic reticulum (SR) membranes with a dissociation constant of 1.7 ± 0.6 mg of phosphorylase/ml at 25°C at physiological pH and ionic strength. Raising the temperature to 37°C produced a 2-3-fold decrease in the dissociation constant. The SR membranes could bind up to 1.1 ± 0.1 mg of glycogen phosphorylase b/mg of SR protein, whereas liposomes prepared with endogenous SR lipids and reconstituted Ca-ATPase were unable to bind glycogen phosphorylase. Binding of glycogen phosphorylase b to SR membranes is accompanied by inhibition of its activity in the presence of AMP. The Vmax for glycogen phosphorylase b associated with SR membranes is 40 ± 5% of that for purified glycogen phosphorylase and shows a decreased affinity for its allosteric activators, AMP and IMP. These kinetic effects are also observed with purified glycogen phosphorylase b when starch or α-amylose is used as substrate instead of glycogen. Treatment of SR membranes with α-amylase produced dissociation of glycogen phosphorylase b from the SR membranes. Thus, linear polysaccharide fragments of glycogen bound to the SR membranes are likely mediating the binding of glycogen phosphorylase b to these membranes.
DOI：
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发表时间：
1986-05
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
G. Meissner
通讯作者：
G. Meissner
ATP 从钙 ATP 酶中缓慢解离。
DOI：
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发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Pickart,CM;Jencks,WP
通讯作者：
Jencks,WP