Riddell F G, Zhou Z
School of Chemistry, University of St. Andrews, Scotland.
J Inorg Biochem. 1994 Sep;55(4):279-93. doi: 10.1016/0162-0134(94)85012-7.
One major problem in using NMR to study halide ions in biological and model biological systems has been to find a contrast reagent to differentiate between halide ions in different compartments. Mn2+ is shown to be a very efficient NMR relaxation agent for the halide ions chloride and bromide and preferable to Co2+ at high magnetic fields. Its use is demonstrated in experiments in which halide ions are exchanged across the membranes of egg yolk phosphatidylcholine vesicles by the phase transfer catalysts tetrabutylammonium ion and benzyltributylammonium ion. Benzyltributylammonium ion is shown to be the more rapid anion transporter through the membrane. Valinomycin is found to cotransport ammonium ions with chloride as an ion pair at a faster rate than the phase transfer catalysts.
利用核磁共振（NMR）研究生物及模型生物体系中的卤离子时，一个主要问题是找到一种对比试剂，以区分不同区室中的卤离子。结果表明，Mn2+ 是卤离子氯离子和溴离子非常有效的NMR弛豫剂，在高磁场下比Co2+ 更具优势。在实验中展示了其用途，在这些实验中，卤离子通过相转移催化剂四丁基铵离子和苄基三丁基铵离子在蛋黄磷脂酰胆碱囊泡膜间进行交换。结果表明，苄基三丁基铵离子是穿过膜的更快的阴离子转运体。发现缬氨霉素能以比相转移催化剂更快的速率将铵离子与氯离子作为离子对进行共转运。
