Gust D, Moon R B, Roberts J D
Proc Natl Acad Sci U S A. 1975 Dec;72(12):4696-700. doi: 10.1073/pnas.72.12.4696.
Natural-abundance nitrogen-15 nuclear magnetic resonance spectroscopy of enzymes and other biopolymers is found to be feasible using newly available instrumentation. The long correlation times of such molecules result in short spin-lattice relaxation times, and these in turn allow rapid signal accumulation. The advantages of short T1 values are sometimes offset, however, by unfavorable nuclear Overhauser effects. The dependence of T1 and nuclear Overhauser effects upon correlation time is discussed, and preliminary nitrogen-15 nuclear magnetic resonance results for several biopolymers, including lysozyme, protamines, pepsin, hemoglobin, vitamin B 12, and tRNA, are presented.
利用新获得的仪器设备,发现对酶和其他生物聚合物进行天然丰度氮 - 15核磁共振波谱分析是可行的。这类分子的长相关时间导致短的自旋晶格弛豫时间,而这反过来又使得信号能够快速积累。然而,短T1值的优势有时会被不利的核Overhauser效应抵消。讨论了T1和核Overhauser效应与相关时间的关系,并给出了几种生物聚合物(包括溶菌酶、鱼精蛋白、胃蛋白酶、血红蛋白、维生素B12和tRNA)的初步氮 - 15核磁共振结果。