Chen C, Feng Y, Short J H, Wand A J
Department of Biochemistry, University of Illinois at Urbana, Champaign 61801.
Arch Biochem Biophys. 1993 Nov 1;306(2):510-4. doi: 10.1006/abbi.1993.1544.
The main chain dynamics of a peptide corresponding to the smooth muscle myosin light chain kinase calmodulin-binding domain bound to calcium-saturated calmodulin have been studied by 15N relaxation techniques. Laboratory and rotating-frame spin lattice relaxation times and nuclear Overhauser effects have been determined for nine amide 15N sites in the peptide using two-dimensional NMR spectroscopy. The global motion of the 1:1 complex is shown to be isotropic and is characterized by a correlation time of 10 ns rad-1. The generalized order parameters (S2) of the nine backbone amide N-H vectors of the peptide all fall closely about a value of 0.83. The corresponding effective correlation times all tend to zero, indicating that, on the subnanosecond time scale, backbone motion of the bound peptide is highly restricted and dominated by extremely fast motions.
通过15N弛豫技术研究了与钙饱和钙调蛋白结合的平滑肌肌球蛋白轻链激酶钙调蛋白结合结构域对应肽段的主链动力学。使用二维核磁共振光谱法测定了该肽段中九个酰胺15N位点的实验室和旋转框架自旋晶格弛豫时间以及核Overhauser效应。结果表明，1:1复合物的整体运动是各向同性的，其特征相关时间为10 ns rad-1。该肽段九个主链酰胺N-H向量的广义序参数（S2）均紧密围绕0.83的值。相应的有效相关时间均趋于零，这表明在亚纳秒时间尺度上，结合肽段的主链运动受到高度限制，且主要由极快的运动主导。
