Swanson S D, Bryant R G
Department of Chemistry, University of Rochester Medical Center, New York 14642.
Biopolymers. 1991 Jul;31(8):967-73. doi: 10.1002/bip.360310806.
13C-nmr measurements are reported for samples of poly (L-lysine) both static and spinning at the magic angle in the beta-sheet form as a function of water content. The addition of water decreases the side-chain line widths considerably. Measurements of the cross-polarization time constants indicate that hydration by either H2O or D2O increases the time constant. Measurements of spin-lattice relaxation times in the laboratory frame and the rotating frame indicate that hydration does not change the dynamics of the backbone carbon atoms in the beta-sheet structure appreciably, but the side-chain atoms experience considerable increase in local mobility with increasing hydration. Deuteration of the exchangeable protons or the water has only small effects on the carbon relaxation times, indicating that relaxation is driven by intramolecular dipole-dipole interactions.
报道了聚（L-赖氨酸）样品在β-折叠形式下，于魔角静态和旋转时，作为含水量函数的13C核磁共振测量结果。水的加入显著降低了侧链线宽。交叉极化时间常数的测量表明，H2O或D2O的水合作用增加了时间常数。实验室坐标系和旋转坐标系中自旋晶格弛豫时间的测量表明，水合作用不会明显改变β-折叠结构中主链碳原子的动力学，但随着水合作用的增加，侧链原子的局部流动性显著增加。可交换质子或水的氘代对碳弛豫时间只有很小的影响，表明弛豫是由分子内偶极-偶极相互作用驱动的。
