Molecular extensibility of mini-dystrophins and a dystrophin rod construct
Molecular extensibility of mini-dystrophins and a dystrophin rod construct
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DOI：
10.1016/j.jmb.2005.07.064
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发表时间：
2005-09-30
影响因子：
5.6
通讯作者：
Discher, DE
中科院分区：
文献类型：
--
作者：
Bhasin, N;Law, R;Discher, DE
肌营养不良与肌营养不良蛋白的各种突变有关，这暗示了这种蛋白质在正常肌肉中的力传递。肌营养不良蛋白有24个三螺旋，血影蛋白重复序列散布着富含脯氨酸的铰链，其大的尺寸是基因治疗的障碍，促进了微型肌营养不良蛋白的构建。营养不良小鼠的结果表明，重复序列之间至少有一个铰链是必要的，但不足以缓解效果。一个这样的迷你肌营养不良蛋白在这里研究在单分子水平上的强制延伸。Delta 2331由重复序列（R）和铰链（H）H1-R1-2组成，类似于H3，类似于R22-24-H4，通过天然连接。(-)和非天然（类似于）序列。这与其核心片段R2（类似于H3，类似于R22）以及八重复杆片段中间（RFM：R8-15）进行比较。我们通过原子力显微镜显示，所有重复序列的延伸和展开力与几个肌球蛋白分子可以产生的力相当。铰链区最常延伸并传递力，同时限制串联重复展开。从23-42摄氏度，肌营养不良蛋白构建体在解折叠中与充分研究的I-血影蛋白构建体相比也表现出较低的温度敏感性。因此，结果揭示了肌营养不良蛋白的灵活性，可能证明中央肌营养不良蛋白和迷你肌营养不良蛋白的功能的新模式。(c)2005爱思唯尔有限公司保留所有权利。
Muscular dystrophies arise with various mutations in dystrophin, implicating this protein in force transmission in normal muscle. With 24 three-helix, spectrin repeats interspersed with proline-rich hinges, dystrophin's large size is an impediment to gene therapy, prompting the construction of mini-dystrophins. Results thus far in dystrophic mice suggest that at least one hinge between repeats is necessary though not sufficient for palliative effect. One such mini-dystrophin is studied here in forced extension at the single molecule level. Delta 2331 consists of repeats (R) and hinges (H) H1-R1-2 similar to H3 similar to R22-24-H4 linked by native. (-) and non-native (similar to) sequence. This is compared to its core fragment R2 similar to H3 similar to R22 as well as an eight-repeat rod fragment middle (RFM: R8-15). We show by atomic force microscopy that all repeats extend and unfold at forces comparable to those that a few myosin molecules can generate. The hinge regions most often extend and transmit force while limiting tandem repeat unfolding. From 23-42 degrees C, the dystrophin constructs also appear less temperature-sensitive in unfolding compared to a well-studied I-spectrin construct. The results thus reveal new modes of dystrophin flexibility that may prove central to functions of both dystrophin and mini-dystrophins. (c) 2005 Elsevier Ltd. All rights reserved.