Molecular movements promoted by metal nucleotides in the heavy-chain regions of myosin heads from skeletal muscle.
Molecular movements promoted by metal nucleotides in the heavy-chain regions of myosin heads from skeletal muscle.
复制标题
骨骼肌肌球蛋白头重链区域的金属核苷酸促进分子运动。
DOI：
10.1016/0022-2836(85)90015-4
复制
发表时间：
1985
影响因子：
5.6
通讯作者：
R. Kassab
中科院分区：
文献类型：
--
作者：
D. Mornet;P. Pantel;E. Audemard;J. Derancourt;R. Kassab
研究了肌球蛋白S1‡重链(27-50-20(×10~3)mR)区域与核苷酸相互作用时的分子运动。用核苷酸促进NH2末端27×103mR和50×103mR片段转化为22×103mR和45×103mR产物的速率和程度来确定分子运动的幅度。氨基酸序列研究表明，22×103MR多肽来源于Arg和Ile(第23-24位)之间的肽键断裂。45×103MR多肽，先前被证明代表50×103MR区域的NH2末端部分，将通过一个约5×103MR的环段连接到相邻的C-末端20×103MR区域；后者的蛋白分解敏感性特别是通过核苷酸结合而增加。胰酶反应被证明是连接的重链构象状态的敏感指标，因为这两个区域的多肽键断裂速度取决于结合的配体和性质；按以下顺序递减：ATP>；AMPPNP>；ADP>；PPI。F-肌动蛋白与S1-−-MAMPPNP复合体的结合对27×103mR和50×103mR多肽的断裂具有显著的保护作用，但伴随着50×103mR-20×103mR连接的水解性。此外，镁ATP与HMM的相互作用调节S1-S2区的胰酶分裂。所有的数据为肌球蛋白头部的两态模型提供了分子支持，并强调了50×103MR单元参与了肌动蛋白和核苷酸结合位点之间的偶联机制。
Molecular movements generated in the heavy-chain regions (27-50-20(× 103)Mr) of myosin S1‡on interaction with nucleotides ATP, AMPPNP, ADP and PPiwere investigated by limited proteolysis of several enzyme-metal nucleotide complexes in the absence and presence of reversibly bound and crosslinked F-actin. The rate and extent of the nucleotidepromoted conversion of the NH2-terminal 27 × 103Mrand 50 × 103Mrsegments into products of 22 × 103Mrand 45 × 103Mr, respectively, were estimated to determine the amplitude of the molecular movements. The 22 × 103Mrpeptide was identified by amino acid sequence studies as being derived from cleavage of the peptide bond between Arg and Ile (at position 23 to 24).The 45 × 103Mr, peptide, previously shown to represent the NH2-terminal part of the 50 × 103Mrregion, would be connected to the adjacent C-terminal 20 × 103Mrregion by a pre-existing loop segment of about 5 × 103Mr; the proteolytic sensitivity of the latter region is increased particularly by nucleotide binding.The tryptic reaction proved to be a sensitive indicator of the conformational state of the liganded heavy chain as the rate of peptide bond cleavage in the two regions is dependent on the nature of the bound ligand; it decreases in the order: ATP > AMPPNP > ADP > PPi. It depends also on the nature of the metal present, Mg2+and Ca2+being much more effective than K+.Binding of F-actin to the S1-MgAMPPNP complex affords significant protection against breakdown of 27 × 103Mrand 50 × 103Mrpeptides, but with concomitant hydrolysis of the 50 × 103Mr−20 × 103Mrjunction. Additionally, interaction of MgATP with HMM modulates the tryptic fission of the S1-S2 region. The overall data provide a molecular support for the two-state model of the myosin head and emphasize the involvement of the 50 × 103Mrunit in the mechanism of coupling between the actin and nucleotide binding sites.
登录
查看更多内容
肌球蛋白亚片段 1 蛋白水解敏感区域中核苷酸诱导的变化。
影响因子：
2.9
作者：
Applegate,D;Reisler,E
通讯作者：
Reisler,E
胰蛋白酶消化对肌球蛋白亚片段 1 及其肌动蛋白激活的腺苷三磷酸酶的影响。
影响因子：
2.9
作者：
Botts,J;Muhlrad,A;Takashi,R;Morales,MF
通讯作者：
Morales,MF
肌球蛋白亚片段的交联 1.通过多种双功能试剂进行核苷酸增强修饰。
DOI：
--
发表时间：
1980
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Wells,JA;Knoeber,C;Sheldon,MC;Werber,MM;Yount,RG
通讯作者：
Yount,RG
DOI：
--
发表时间：
1984
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Mahmood,R;Yount,RG
通讯作者：
Yount,RG
核苷酸、二价阳离子和温度对肌球蛋白亚片段 1 胰蛋白酶敏感性的影响。
DOI：
10.1111/j.1432-1033.1984.tb08542.x
发表时间：
1984
期刊：
European journal of biochemistry
影响因子：
--
作者：
Mocz,G;Szilagyi,L;ChenLu,R;Fabian,F;Balint,M;Gergely,J
通讯作者：
Gergely,J