Wu Zhengrong, Bax Ad
Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Am Chem Soc. 2002 Aug 21;124(33):9672-3. doi: 10.1021/ja026845n.
Measurement of 1H-1H dipolar couplings in macromolecules, weakly oriented by a dilute liquid crystalline medium, is generally limited to the largest such interactions. By removing dipolar couplings to nearest neighbors, either by decoupling, deuteration, or both, more remote interactions become accessible. The approach is demonstrated for measurement of amide-amide interactions in the proteins calmodulin and ubiquitin and permits observation of direct dipolar couplings between protons up to 7 A apart. Quantitative evaluation of 1H-1H dipolar couplings measured in ubiquitin shows excellent agreement with its solution structure.
在由稀液晶介质弱取向的大分子中测量1H-1H偶极耦合，通常仅限于最大的此类相互作用。通过去耦、氘代或两者结合去除与最近邻的偶极耦合，更远程的相互作用就可以被检测到。该方法在测量钙调蛋白和泛素中酰胺-酰胺相互作用时得到了验证，并能够观测到相距达7埃的质子之间的直接偶极耦合。对泛素中测量的1H-1H偶极耦合进行的定量评估与其溶液结构显示出极佳的一致性。
