Kennedy S D, Bryant R G
Department of Biophysics, University of Rochester Medical Center, New York 14642.
Biopolymers. 1990 Dec;29(14):1801-6. doi: 10.1002/bip.360291411.
13C-nmr spectra of lysozyme obtained at 50.3 MHz using both static and magic-angle-spinning-cross-polarization methods are reported at several water contents. The line widths and consequent resolution in the hydrated material is substantially improved over that in the lyophilized protein. The line narrowing is not commensurate with loss of a proton-carbon dipole-dipole coupling or dramatic changes in the relaxation parameters characterizing magnetization transfer from protons to carbon in the Hartmann-Hahn cross-polarization experiment. We interpret these data in terms of the water inducing a decrease in the distribution of local conformations sampled by the protein, although the magnitude of the conformational reorientations required to account for the data are not necessarily large nor do they imply a major unfolding of the protein on dehydration.
报道了在几种含水量下，使用静态和魔角旋转交叉极化方法在50.3MHz下获得的溶菌酶的13C核磁共振谱。与冻干蛋白质相比，水合材料中的线宽和分辨率有了显著提高。线宽变窄与质子-碳偶极-偶极耦合的丧失或在哈特曼-哈恩交叉极化实验中表征从质子到碳的磁化转移的弛豫参数的显著变化并不相称。我们根据水导致蛋白质采样的局部构象分布减少来解释这些数据，尽管解释这些数据所需的构象重排幅度不一定很大，也不意味着蛋白质在脱水时会发生重大展开。
