Department of Chemistry, University of Cambridge, Cambridge, UK.
FEBS Lett. 2010 Mar 19;584(6):1235-9. doi: 10.1016/j.febslet.2010.02.035. Epub 2010 Feb 18.
The giant protein titin, which comprises immunoglobulin (Ig) domains, acts as a bidirectional spring in muscle. The unfolding of Ig domains has been extensively studied, but their dynamics under native states have not been well-characterized. We performed molecular dynamics simulation on a single titin Ig domain and multi-domains. Mobile regions displaying concerted motions were identified. The dynamics of Ig domains are constrained by evolutionary pressures, in such a way that global dominant motion is conserved, yet different flexibilities within Ig domains and in linkers connecting neighbouring domains were observed. We explain these heterogeneous conserved dynamics in relation to sequence conservation across species and the sequence diversity among neighbouring Ig domains.
巨大的蛋白titin 由免疫球蛋白（Ig）结构域组成，在肌肉中充当双向弹簧。Ig 结构域的展开已被广泛研究，但它们在天然状态下的动力学特性尚未得到很好的描述。我们对单个 titin Ig 结构域和多结构域进行了分子动力学模拟。鉴定出显示协同运动的移动区域。Ig 结构域的动力学受到进化压力的限制，使得全局主导运动得以保留，但在相邻结构域之间的连接区中观察到 Ig 结构域内和连接区内的不同灵活性。我们解释了这些异构的保守动力学与跨物种的序列保守性以及相邻 Ig 结构域之间的序列多样性之间的关系。
