Wöhnert Jens, Franz Katherine J, Nitz Mark, Imperiali Barbara, Schwalbe Harald
Institut für Organische Chemie und Chemische Biologie, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe-Universität Frankfurt, Marie-Curie-Strasse 11, 60439 Frankfurt/M, Germany.
J Am Chem Soc. 2003 Nov 5;125(44):13338-9. doi: 10.1021/ja036022d.
A protein fusion construct of human ubiquitin with an N-terminal lanthanide binding tag (LBT) enables observation of long-range orientational restraints in solution NMR from residual dipolar couplings (RDCs) due to paramagnetic alignment of the protein. The paramagnetic lanthanide ions Tb3+, Dy3+, and Tm3+ are shown to bind to the LBT and induce different alignment tensors, in agreement with theory. RDCs, measured relative to the diamagnetic Lu3+, range from -7.6 to 5.5 Hz for Tb3+ and -6.6 to 6.1 Hz for Dy3+, while an opposite alignment tensor is observed for Tm3+ (4.5 to -2.9 Hz) at 800 MHz. Experimental RDCs are in excellent agreement with those predicted on the basis of the X-ray structure of the protein.
一种将人泛素与N端镧系元素结合标签（LBT）融合的蛋白质构建体，能够通过蛋白质顺磁排列产生的残余偶极耦合（RDC），在溶液核磁共振中观察到长程取向限制。顺磁镧系离子Tb3 +、Dy3 +和Tm3 +显示与LBT结合并诱导不同的排列张量，这与理论相符。相对于抗磁的Lu3 +测量的RDC，对于Tb3 +范围为-7.6至5.5 Hz，对于Dy3 +范围为-6.6至6.1 Hz，而在800 MHz下观察到Tm3 +的排列张量相反（4.5至-2.9 Hz）。实验得到的RDC与基于蛋白质X射线结构预测的结果高度吻合。
