Magnetic resonance spectra of membranes.
Magnetic resonance spectra of membranes.
复制标题
膜的磁共振谱。
DOI：
10.1073/pnas.72.4.1451
复制
发表时间：
1975
影响因子：
11.1
通讯作者：
H. Mcconnell
中科院分区：
文献类型：
--
作者：
P. Brûlet;H. Mcconnell
许多模型膜和生物膜的电子和核磁共振研究涉及相对于彼此的时间依赖的磁相互作用扩散。由于该运动调制的磁相互作用相关函数的长尾，该运动的二维特性对磁共振线形状和弛豫率有特殊的、大的影响。给出了由于与膜结合自旋标签的偶极相互作用而使核弛豫率增强的具体情况的方程。用这一理论解释了磷脂酰胆碱非超声分散体中自旋标签增强的13-C核弛豫的实验研究，以及先前报道的脂质扩散常数D等于2乘以10-负8 cm-2/sec。我们对先前报道的超声产生的磷脂小泡中的1-H和13-C核弛豫速率的分析表明，这些小泡中的横向扩散速率可能显著大于10-负8 cm-2/秒。
A number of electron and nuclear magnetic resonance studies of model membranes, and biological membranes, involve time-dependent magnetic interactions diffusion relative to one another. The two-dimensional character of this motion can have a special, large effect on magnetic resonance line shapes, and relaxation rates, because of the long-time tail of the correlation function for magnetic interactions modulated by this motion. Equations are given for the specific case in which nuclear relaxation rates are enhanced due to dipolar interactions with membrane-bound spin labels. An experimental study of spin-label-enhanced 13-C nuclear relaxation in unsonicated dispersions of phosphatidylcholine is accounted for with this theory, together with the previously reported lipid diffusion constant of D congruent to 2 times 10- minus 8 cm-2/sec. Our analysis of previously reported 1-H and 13-C nuclear relaxation rates in small phospholipid vesicles produced by sonication suggests that the rate of lateral diffusion in these small vesicles may be significantly larger than 10- minus 8 cm-2/sec.