Effect of phospholipid, detergent and protein-protein interaction on stability and phosphoenzyme isomerization of soluble sarcoplasmic reticulum Ca-ATPase.
Effect of phospholipid, detergent and protein-protein interaction on stability and phosphoenzyme isomerization of soluble sarcoplasmic reticulum Ca-ATPase.
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磷脂、去垢剂和蛋白质-蛋白质相互作用对可溶性肌浆网 Ca-ATP 酶稳定性和磷酸酶异构化的影响。
DOI：
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
J. Andersen
中科院分区：
文献类型：
--
作者：
B. Vilsen;J. Andersen
本研究的目的是阐明脂类、洗涤剂和蛋白质-蛋白质相互作用对非离子洗涤剂八(乙二醇单十二烷基醚)(C12E8)中肌浆网Ca-ATPase稳定性和催化性能的影响。利用大区域高效液相色谱法，我们可以确定不同洗涤剂、磷脂和蛋白质浓度下的Ca-ATPase多肽的自结合状态，以及在酶与ATP的转换过程中的自结合状态。建立了在相对于洗涤剂有较高浓度磷脂存在的情况下进行Ca-ATPase单体聚合的条件。在无钙条件下，脂饱和单体制剂相对耐失活，而脱脂酶以单体或寡聚形式易失活。研究了在有无镁离子存在的情况下，光合酶的转化动力学。去磷酸化速率对镁离子很敏感，无论肽是以可溶性单体形式存在还是以膜结合的形式存在。然而，在没有添加磷脂的情况下，C12E8增溶的单体在没有镁离子的情况下具有快速的脱磷起始阶段的特征。饱和磷脂的单体或溶解在肉豆蔻酰甘油磷胆碱或脱氧胆酸盐中的单体不能观察到这一点。这种差异的机制是C12E8诱导ADP敏感的磷酸酶(E1P)向ADP不敏感的磷酸酶(E2P)转化的加速。磷酸酶异构化速率也被发现被低亲和力结合的ATP提高。这在膜结合型和可溶性单体Ca-ATPase中都得到了证实。我们的结果表明，镁离子和三磷酸腺苷调节磷酸酶周转的靶标是单肽链，而洗涤作用是C12E8溶解的和膜结合的酶制剂之间动力学差异的主要决定因素，而洗涤作用不同于蛋白质-蛋白质接触的破坏。
The purpose of the present study was to elucidate the separate roles of lipid, detergent and protein-protein interaction for stability and catalytic properties of sarcoplasmic reticulum Ca-ATPase solubilized in the non-ionic detergent octa(ethylene glycol) monododecyl ether (C12E8). The use of large-zone high-performance liquid chromatography permitted us to define the self-association state of Ca-ATPase peptide at various detergent, phospholipid and protein concentrations, and also during enzymatic turnover with ATP. Conditions were established for monomerization of Ca-ATPase in the presence of a high concentration of phospholipid relative to detergent. The lipid-saturated monomeric preparation was relatively resistant to inactivation in the absence of Ca2+, whereas delipidated enzyme in monomeric or in oligomeric form was prone to inactivation. Kinetics of phosphoenzyme turnover were examined in the presence and absence of Mg2+. Dephosphorylation rates were sensitive to Mg2+, irrespective of whether the peptide was present in soluble monomeric form or was membrane-bound. C12E8-solubilized monomer without added phospholipid was, however, characterized by a fast initial phase of dephosphorylation in the absence of Mg2+. This was not observed with monomer saturated with phospholipid or with monomer solubilized in myristoylglycerophosphocholine or deoxycholate. The mechanism underlying this difference was shown to be a C12E8-induced acceleration of conversion of ADP-sensitive phosphoenzyme (E1P) to ADP-insensitive phosphoenzyme (E2P). The phosphoenzyme isomerization rate was also found to be enhanced by low-affinity binding of ATP. This was demonstrated both in membrane-bound and in soluble monomeric Ca-ATPase. Our results indicate that a single peptide chain constitutes the target for modulation of phosphoenzyme turnover by Mg2+ and ATP, and that detergent effects, distinct from those arising from disruption of protein-protein contacts, are the major determinants of kinetic differences between C12E8-solubilized and membrane-bound enzyme preparations.
单体溶解的肌浆网 Ca 泵蛋白：演示 Ca 结合和解离与 ATP 水解的耦合。
DOI：
10.1073/pnas.81.21.6623
发表时间：
1984
影响因子：
11.1
作者：
Martin,DW;Tanford,C;Reynolds,JA
通讯作者：
Reynolds,JA
压力对肌浆网的影响。
DOI：
--
发表时间：
1986
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Varga,S;Mullner,N;Pikula,S;Papp,S;Varga,K;Martonosi,A
通讯作者：
Martonosi,A