Laboratory of Physical Chemistry, ETH Zurich, Wolfgang Pauli Strasse 10, 8093 Zurich (Switzerland).
Chembiochem. 2013 Sep 23;14(14):1883-90. doi: 10.1002/cbic.201300165. Epub 2013 Jun 14.
Lanthanide-induced enhancement of the longitudinal relaxation of nitroxide radicals in combination with orthogonal site-directed spin labeling is presented as a systematic distance measurement method intended for studies of bio-macromolecules and bio-macromolecular complexes. The approach is tested on a water-soluble protein (T4-lysozyme) for two different commercially available lanthanide labels, and complemented by previously reported data on a membrane-inserted polypeptide. Single temperature measurements are shown to be sufficient for reliable distance determination, with an upper measurable distance limit of about 5-6 nm. The extracted averaged distances represent the closest approach in Ln(III) -nitroxide distance distributions. Studies of conformational changes and of bio-macromolecule association-dissociation are proposed as possible application area of the relaxation-enhancement-based distance measurements.
镧系元素诱导的氮氧自由基的纵向弛豫增强与正交的定点自旋标记相结合，被提出作为一种系统的距离测量方法，旨在研究生物大分子和生物大分子复合物。该方法在两种不同的商业镧系元素标记的水溶性蛋白质（T4 溶菌酶）上进行了测试，并补充了以前报道的关于插入膜的多肽的数据。单次温度测量足以进行可靠的距离测定，可测量的最大距离极限约为 5-6nm。提取的平均距离代表了 Ln(III)-氮氧自由基距离分布中最近的接近距离。构象变化和生物大分子的缔合-解离的研究被提出作为基于弛豫增强的距离测量的可能应用领域。
