DETERMINATION OF THE DISTANCE BETWEEN 2 SPIN LABELS ATTACHED TO A MACROMOLECULE
DETERMINATION OF THE DISTANCE BETWEEN 2 SPIN LABELS ATTACHED TO A MACROMOLECULE
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DOI：
10.1073/pnas.92.18.8239
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发表时间：
1995-08-29
影响因子：
11.1
通讯作者：
SHIN, YK
中科院分区：
文献类型：
--
作者：
RABENSTEIN, MD;SHIN, YK
EPR“光谱规则”是使用一系列α-螺旋多肽开发的，每个多肽都用两个氮氧自旋标记修饰。EPR谱线展宽由于电子-电子偶极相互作用在冻结状态下使用傅立叶去卷积方法确定。然后使用这些偶极光谱来估计相隔8-25埃的两个氮氧自由基之间的距离。结果与一个简单的α-螺旋模型一致。在8-25埃的范围内，模型系统的标准偏差为0.9埃。这种技术适用于复杂的系统，如膜受体和通道，这是很难访问与高分辨率NMR或X射线晶体学，并预计将是特别有用的系统，光学方法的光干扰膜或发色团的存在下受到阻碍。
An EPR ''spectroscopic ruler'' was developed using a series of alpha-helical polypeptides, each modified with two nitroxide spin labels. The EPR line broadening due to electron-electron dipolar interactions in the frozen state was determined using the Fourier deconvolution method. These dipolar spectra were then used to estimate the distances between the two nitroxides separated by 8-25 Angstrom. Results agreed well with a simple alpha-helical model. The standard deviation from the model system was 0.9 Angstrom in the range of 8-25 Angstrom. This technique is applicable to complex systems such as membrane receptors and channels, which are difficult to access with high-resolution NMR or x-ray crystallography, and is expected to be particularly useful for systems for which optical methods are hampered by the presence of light-interfering membranes or chromophores.