Hybrid formation between scallop myofibrils and foreign regulatory light-chains.
Hybrid formation between scallop myofibrils and foreign regulatory light-chains.
复制标题
扇贝肌原纤维和外来调节轻链之间的杂交形成。
DOI：
10.1016/0022-2836(80)90088-1
复制
发表时间：
1980
影响因子：
5.6
通讯作者：
Szent-Györgyi,AG
中科院分区：
文献类型：
--
作者：
Sellers,JR;Chantler,PD;Szent-Györgyi,AG
扇贝肌原纤维 (Placopecten magellanicus) 的调节轻链已通过 EDTA 在 30 °C 下处理完全去除，与不同肌球蛋白的调节轻链杂交。纯杂交体仅含有化学计量为每个肌球蛋白两摩尔的外来调节轻链，很容易与所有测试的轻链形成。在缺钙的情况下，一些调节轻链通过选择性抑制肌动蛋白激活的 Mg-ATP 酶，恢复了脱敏肌原纤维的调节功能。来自Mercenaria、Spisula Loligo 和Urechis 的轻链表现为扇贝调节轻链，在没有钙的情况下具有抑制作用，并恢复高亲和力的钙结合位点。鲎、蟋蟀、鸡胗和血小板的调节轻链也具有抑制作用；然而，钙结合以较低的亲和力恢复，并且杂交体需要更高的钙浓度来激活 ATP 酶。用脊椎动物横纹动物（兔、鸡、鳐鱼）、牛心脏和龙虾尾部和爪肌的调节轻链形成的杂交体对钙仍然不敏感，它们的ATP酶活性在没有钙的情况下不会被选择性地抑制，并且特定的高亲和力钙结合位点不会恢复。轻链（兔、贲门和肌胃）的磷酸化对 ATP 酶活性没有影响。杂交体的行为支持这样的解释：在脊椎动物横纹肌中，肌球蛋白不发挥调节开关的作用。外来调节轻链（Spisula、Loligo、Mercenaria、兔子）以与扇贝调节轻链相似或稍高的亲和力与脱敏肌原纤维结合。肌球蛋白的两个轻链结合位点是相同的，并且亲和力的差异似乎是肌球蛋白分子的两半之间相互作用的结果。
Scallop myofibrils (Placopecten magellanicus) from which regulatory light-chains had been completely removed by EDTA treatment at 30 °C were hybridized with regulatory light-chains of different myosins. Pure hybrids, containing only foreign regulatory light-chains with a stoichiometry of two moles per myosin, were readily formed with all the light-chains tested. Some of the regulatory light-chains restored regulatory functions to desensitized myofibrils by selectively inhibiting the actin activated Mg-ATPase in the absence of calcium. Light-chains fromMercenaria, Spisula LoligoandUrechisbehaved as scallop regulatory light-chains, were inhibitory in the absence of calcium, and restored high-affinity calcium binding sites. Regulatory light-chains ofLimulus, cricket, chicken gizzard and platelet were also inhibitory; however, calcium binding was restored with a lowered affinity and the hybrids required higher calcium concentrations for ATPase activation. Hybrids formed with the regulatory light-chains of vertebrate striated (rabbit, chicken, skate), bovine cardiac and lobster tail and claw muscles remained insensitive to calcium, their ATPase activity was not selectively depressed in the absence of calcium and specific high-affinity calcium binding sites were not restored. Phosphorylation of the light-chains (rabbit, cardiac and gizzard) has no effect on ATPase activity. The behaviour of the hybrids supports the interpretation that in vertebrate striated muscles myosin does not function as a regulatory switch.Foreign regulatory light-chains (Spisula, Loligo, Mercenaria, rabbit) bind to desensitized myofibrils with a similar or slightly higher affinity as scallop regulatory light-chains. The two light-chain binding sites of myosin are equivalent and differences in affinity appear to be the result of an interaction between the two halves of the myosin molecules.
登录
查看更多内容
组织化学鉴定的兔腰肌纤维中肌球蛋白轻链的表征
影响因子：
3.5
作者：
A. Weeds;R. Hall;N. Spurway
通讯作者：
N. Spurway
肌球蛋白轻链
影响因子：
64.8
作者：
A. Weeds
通讯作者：
A. Weeds
鸡肫：钙激活磷酸化与收缩的关系。
影响因子：
56.9
作者：
P. E. Hoar;W. Kerrick;P. Cassidy
通讯作者：
P. Cassidy
脊椎动物平滑肌肌动蛋白-肌球蛋白相互作用的调节：通过肌球蛋白轻链激酶激活和原肌球蛋白的作用。
影响因子：
5.6
作者：
A. Sobieszek;J. Small
通讯作者：
J. Small
无脊椎动物肌球蛋白和轻链的光谱研究。
影响因子：
2.9
作者：
P. Chantler;A. Szent
通讯作者：
A. Szent