Mechanics of glycerinated muscle fibers using nonnucleoside triphosphate substrates.
Mechanics of glycerinated muscle fibers using nonnucleoside triphosphate substrates.
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使用非核苷三磷酸底物的甘油肌纤维的力学。
DOI：
10.1016/s0006-3495(91)82275-5
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发表时间：
1991
影响因子：
3.4
通讯作者：
Cooke,R
中科院分区：
文献类型：
--
作者：
Pate,E;Nakamaye,KL;Franks-Skiba,K;Yount,RG;Cooke,R
我们研究了光亲和性，非核苷酸ATP类似物，2-[（4-叠氮基-2-硝基苯基）氨基]乙基三磷酸（NANTP）和2-[（4-叠氮基-2-硝基苯基）氨基]丙基三磷酸（PrNANTP），以支持甘油兔腰肌纤维的主动收缩的能力。在毫摩尔浓度下，在没有钙的情况下，这两种类似物都使纤维松弛。在钙的存在下，MgNANTP产生的等长张力和刚度的二分之一至三分之二的MgATP中获得的值。最大缩短速度和钙激活，肌原纤维催化的水解速率大致相同的MgNANTP为MgATP。以MgNANTP为底物，增加浓度的二磷酸类似物，MgNANDP，抑制缩短速度，但不改变等长张力。增加正磷酸盐（P）的浓度降低张力，而缩短速度增加。因此，NANTP的水解产物的效果是非常相似的，以前观察到的ADP和P在MgATP的存在下。总之，这些观察结果表明，MgNANTP结合到肌球蛋白的活性位点，并以与MgATP非常类似的方式在肌球蛋白的活性位点中发挥作用。因此，芳基叠氮基应该作为有效的光亲和标记的嘌呤部分的活性位点。相比之下，MgPrNANTP，它不同于MgNANTP之间的硝基苯基环和三磷酸部分的额外的CH 2间隔不支持等距张力或活性缩短在钙的存在下。纤维刚度增加的钙和MgPrNANTP的存在下，与钙激活，肌原纤维MgPrNANTaldehyde，这是约一半，获得与MgATP。因此，在MgPrNANTP的存在下，交叉桥似乎是通过连接到肌动蛋白的状态循环，但不产生力。
We have investigated the ability of the photoaffinity, nonnucleotide ATP analogues, 2-[(4-azido-2-nitrophenyl) amino] ethyl triphosphate (NANTP) and 2-[(4-azido-2-nitrophenyl) amino] propyl triphosphate (PrNANTP), to support active contraction in glycerinated rabbit psoas fibers. At millimolar concentrations, in the absence of calcium, both analogues relaxed fibers. In the presence of calcium, MgNANTP produced isometric tension and stiffness that were one-half to two-thirds the values obtained in MgATP. Maximum shortening velocity and the calcium-activated, myofibrillar catalyzed rate of hydrolysis were approximately the same for MgNANTP as for MgATP. With MgNANTP as the substrate, increasing concentrations of the diphosphate analogue, MgNANDP, inhibited shortening velocity but did not change isometric tension. The addition of increased concentrations of orthophosphate (P) decreased tension while shortening velocity increased. Thus, the effects of the hydrolysis products of NANTP were quite similar to those observed previously for ADP and P in the presence of MgATP. Taken together, these observations show that MgNANTP binds to, and functions in the active site of myosin in a manner quite analogous to MgATP. Thus, the aryl azido group should serve as a valid photoaffinity label for the purine portion of the active site. In contrast, MgPrNANTP, which differs from MgNANTP only in an extra CH2 spacer between the nitrophenyl ring and the triphosphate moiety did not support isometric tension or active shortening in the presence of calcium. Fiber stiffness increased in the presence of calcium and MgPrNANTP, with a calcium-activated, myofibrillar MgPrNANTPase which was about half that obtained with MgATP. Thus, in the presence of MgPrNANTP, cross-bridges appeared to be cycling through states that were attached to actin, but not producing force.
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影响因子：
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作者：
R. Mains;B. Eipper
通讯作者：
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作者：
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DOI：
10.1210/mend-1-8-548
发表时间：
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期刊：
Molecular endocrinology (Baltimore, Md.)
影响因子：
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10.1111/j.1530-0277.1984.tb05712.x
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1984
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Alcoholism, clinical and experimental research
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DOI：
10.1111/j.1530-0277.1983.tb05420.x
发表时间：
1983
期刊：
Alcoholism, clinical and experimental research
影响因子：
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作者：
Gilliam,DM;Bloedow,DC;Collins,AC
通讯作者：
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