Model-independent electron spin resonance for measuring order of immobile components in a biological assembly.
Model-independent electron spin resonance for measuring order of immobile components in a biological assembly.
复制标题
与模型无关的电子自旋共振，用于测量生物组件中固定组件的顺序。
DOI：
10.1016/s0006-3495(85)83796-6
复制
发表时间：
1985
影响因子：
3.4
通讯作者：
Thompson,NL
中科院分区：
文献类型：
--
作者：
Burghardt,TP;Thompson,NL
电子自旋共振（ESR）技术应用于有序生物组件中元素角取向分布的模型无关描述。正如之前的荧光偏振模型无关的处理（Burghardt, t.p., 1984, Biopolymers, 23:2383-2406），元素顺序是通过分子框架的角度分布来描述的，其中一个框架固定在组装的每个元素中。将分布展开为一个完备的标准正交函数集。级数展开的系数（阶数参数）描述了组件中元素的方向分布，无需参考模型，可以从观测到的光谱中获得。该方法通过确定ESR技术可以检测的分布系数，确定了ESR技术在检测装配顺序方面的局限性。提出了一种利用一组ESR基谱从ESR谱中确定阶参量的方法。我们还描述了一种处理方法，该方法结合了从随机定向、不移动元素测量的实际线形。在这种处理中，不需要关于线形的依赖于模型的假设。我们将模型无关分析应用于肌纤维中自旋标记肌球蛋白交叉桥的ESR光谱。结果包含了自旋探针角分布的详细信息，并且与以前依赖于模型的光谱解释有有趣的不同。
A model-independent description of the angular orientation distribution of elements in an ordered biological assembly is applied to the electron spin resonance (ESR) technique. As in a previous model-independent treatment of fluorescence polarization (Burghardt, T.P., 1984, Biopolymers, 23:2383–2406) the elemental order is described by an angular distribution of molecular frames with one frame fixed in each element of the assembly. The distribution is expanded in a complete orthonormal set of functions. The coefficients of the series expansion (the order parameters) describe the orientation distribution of the elements in the assembly without reference to a model and can be obtained from the observed spectrum. The method establishes the limitations of ESR in detecting order in the assembly by determining which distribution coefficients the technique can detect. A method of determining the order parameters from an ESR spectra, using a set of ESR basis spectra, is developed. We also describe a treatment that incorporates the actual line shape measured from randomly oriented, immobile elements. In this treatment, no model-dependent assumptions about the line shape are required. We have applied the model-independent analysis to ESR spectra from spin-labeled myosin cross-bridges in muscle fibers. The results contain detailed information on the spin-probe angular distribution and differ in interesting ways from previous model-dependent interpretations of the spectra.