Molecular alignment of denatured states of staphylococcal nuclease with strained polyacrylamide gels and surfactant liquid crystalline phases.
Molecular alignment of denatured states of staphylococcal nuclease with strained polyacrylamide gels and surfactant liquid crystalline phases.
复制标题
葡萄球菌核酸酶变性状态与应变聚丙烯酰胺凝胶和表面活性剂液晶相的分子排列。
DOI：
10.1021/bi0120796
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发表时间：
2002
期刊：
影响因子：
2.9
通讯作者：
Shortle,David
中科院分区：
文献类型：
--
作者：
Ackerman,MichaelS;Shortle,David
剩余偶极耦合反映了磁核对之间的矢量相对于一组独特的分子轴的取向。因此，与NOE和标量耦合不同，偶极耦合提供了对长程结构信息的访问。测量这些NMR参数的先决条件是施加弱的净排列，最简单的是通过迫使大分子在限制某些取向的非对称环境中翻滚。在这份报告中，几种变性形式的葡萄球菌核酸酶对齐使用压缩和拉伸聚丙烯酰胺凝胶，非离子型的脂质双层磁盘或bicelle，和由阳离子脂质形成的液晶相。所有三种类型的培养基都可以在高尿素浓度下使用。虽然聚丙烯酰胺凝胶和bicelles通过空间相互作用产生类似的对齐张量，但溴化十六烷基吡啶的液晶相可能通过静电效应沿不同的轴沿着对齐变性核酸酶。用两种不同的排列张量收集的残余偶极耦合的分析可以允许计算构象的系综。观察到的偶极偶联葡萄球菌核酸酶与尿素变性，低pH值或从两端删除残基，表明所有变性形式共享一个共同的“拓扑结构”，一个先前已被证明是nativelike。虽然SDS/核酸酶复合物给出了清晰和分散的1H − 15 N相关光谱，但在应变聚丙烯酰胺凝胶中只观察到小的偶联。
Residual dipolar couplings reflect the orientation of vectors between pairs of magnetic nuclei relative to a unique set of molecular axes. Thus, unlike NOEs and scalar couplings, dipolar couplings provide access to long-range structural information. A prerequisite for measurement of these NMR parameters is imposition of a weak net alignment, most simply by forcing the macromolecules to tumble in an asymmetric environment that restricts some orientations more than others. In this report, several denatured forms of staphylococcal nuclease are aligned by using compressed and stretched polyacrylamide gels, a nonionic type of lipid bilayer disk or bicelle, and a liquid crystalline phase formed by a cationic lipid. All three types of media can be used at high urea concentrations. While polyacrylamide gels and bicelles produce similar alignment tensors through steric interactions, a liquid crystalline phase of cetylpyridinium bromide aligns denatured nuclease along a different set of axes, presumably through electrostatic effects. The analysis of residual dipolar couplings collected with two different alignment tensors may permit the calculation of ensembles of conformations. The dipolar couplings observed for staphylococcal nuclease denatured with urea, by low pH or by deletion of residues from both termini, suggest that all denatured forms share a common “topology”, one which has been shown previously to be nativelike. Although SDS/nuclease complexes give sharp and disperse1H−15N correlation spectra, only small couplings are observed in strained polyacrylamide gels.
通过 NMR 方法对蛋白质的非天然状态进行结构分析。
影响因子：
6.8
作者：
D. Shortle
通讯作者：
D. Shortle
影响因子：
2.7
作者：
Skrynnikov, NR;Kay, LE
通讯作者：
Kay, LE
影响因子：
15
作者：
Delaglio, F;Kontaxis, G;Bax, A
通讯作者：
Bax, A